FUNCTION:
I use this for work as an engineer, not gaming so I can't speak to that side of things. I love trackball mice for multiple reasons, but I prefer the index/middle finger ball control like this has. I've been using the Kensington orbit trackball with scroll ring as well as the Logitech MK570. I like both for their own reasons. Primarily the orbit is best for use on documents with the scroll ring and more intuitive (in my opinion) use of index/middle finger ball use. I like the MK570 for use with CAD files because it is nearly imperative to be able to use a scroll wheel click to move or rotate the drawing. It's also nice that the MK570 include the forward/backward buttons for web browsing or navigating the computer's file explorer. I've been using both side by side for years. The HUGE combines the best of both worlds into a single mouse that is superior to either of the others.

The HUGE is perfect for those like me that have a need for the wheel click but prefer the index/middle finger mouse movement. In addition, the location and convenience of the forward/back buttons, it really has everything the everyday user needs. Because I go through a lot of .pdf drawings, I programmed the FN1 and 2 keys for zoom in and zoom out respectively. It helps while going through specifications, plan drawings, etc. Not sure what I'll use the third function for just yet, but it's nice to have options.

FORM:
I'm 6' with what I figure is a fairly normal hand size for my height. I love the size and feel of the HUGE. It may be more comfortable for someone that had a slightly shorter thumb since I have to be conscious of where I place my hand to make the thumb in a location that's easy to use all three buttons on the side. In using the Kensington Orbit and Logitech MK570 I found that the MK570 was more comfortable because of the hand tilt orientation whereas the orbit left a lot of my hand airborn, but had the comfort of the palm rest. The HUGE has a nice squishy palm rest with a comfortable hand tilt for use. There's no need for additional wrist support since they made this thing monstrous to integrate it in. Even with the size of it, it's much smaller than a mousepad so it's still going to save space over typical mice.

Mouse movement is nice and smooth with the larger ball. It also makes it so you don't have to move your fingers as much as the smaller ones (but you can if you have limited finger length) to get across the screen. I sort of enjoy the added inertia of the larger ball. It seems like it makes my movements slightly more precise.

CONCLUSION:
Overall very pleased with the product. It feels very well built, has all the functionality I and the general public need, and it's comfortable. It only took a couple hours to get used to the new layout since I had two different mice that this sort of combines functionally.

Highly recommend, but maybe not for travel.

Have been a Marble user for some time, I prefer trackballs over mice, and further prefer index/middle finger trackballs over the thumb driven variety. Was excited to find this version, and ordered in spite of the mixed reviews. Received it today, and immediately tipped it on an outside angle similar to what the Logitech MX ERGO does. When tipped at about 30° it feels a lot, lot better on the wrist, and motions feel more natural. Am going to mess with it a bit over the next few weeks to see which angle works best. It's counter-intuitive, but positioning your hand further forward than seems normal seems to help the feel out. It does put the trackball in a less efficient position on the fingers, tho.

Controls were a bit stiff, especially the choose button which of course is the most oft used, which I figure will work out at least some over time. Both Marbles were the same way. 3-position mouse speed okay. in a perfect world it'd be nice to fine-tune it.

Apart from the trackball position, the biggest part of purchasing this was to navigate Photoshop, Premier video editing and Lightroom. Plenty of customization options to work with. I downloaded the Mac version of Mouse Assistant prior to the hardware plug-in, which I really wish I had done prior to purchase. Long story short - if you're running Sierra 10.13.2 don't expect the downloaded Assistant software to work. You're going to be stuck with what buttons are doing what and how. I've got the trackball cursor function, up/down on scroll wheel, chooser button on the bottom, and traditional right-click button next to the trackball, and that's it. No function buttons, no scroll tilt, no fine tuning. That was a real disappointment. Looking around the web, I see more than one person had the same thing happen.

I really hate to give this nicely built trackball a 2 star rating, but if the Mac-compatible programming software doesn't pop and work after being advertised that it will, it really detracts from the device's usefulness. Will hold on for a few months to see if things get rectified (or I can find a workaround), but more than likely it'll end up on Craigslist and I'll have a new Logitech and get used to a thumb-style trackball. Would have been a solid 4+ stars had things worked as advertised.

I've owned about a dozen Logitech M570 trackballs and finally got fed up replacing them as they are a great product that wears out ridiculously fast due to cheap components. Wanting to be rid of Logitech's crap, I tried this Elecom trackball. I've used it now for awhile and it's superb. The switches are high quality, the ball is huge (billiard ball or handball size) are roles easily, and the functions, while a bit complex, are very well thought out. Others have complained about the software install which I simple don't understand. The instructions point to a website where I downloaded the application and drivers for Windows 10 64 - they installed without a hitch and I was very quickly operational.

If you're coming off a M570, this takes a bit of time to get accustomed to. It feels awkward at first. The wheel seems to be in the way of your thumb at first. In a few hours, however, I found the layout to be smartly designed and now I can move much faster than I ever could with the M570. Battery longevity has turned out to be very good. The sensitivity adjustment is fantastic, it allows you to choose between 3 settings depending upon you application. So if you need more sensitivity just slide the switch and finer movements are available. The pad for the palm of your hand is very soft and comfortable - another neat thing. The many options for assigning functions through the software make the slightly higher price well worth it.

All-in-all, a topnotch trackball. Since I dumped all of my Logitech keyboards and TV remotes I am now finally rid of their constantly failing products.

I bought this as a promising-looking replacement for the famous, out-of-production Logitech Cordless Optical Trackman. It is also way FLATTER than it appears, so it's actually not ergonomic like the Logitech. The ball on this unit is heavy and solid and top quality--but the ergonomics are BAD for anyone used to the Logitech. Also, the scroll wheel requires bending the thumb awkwardly; it's soooo much worse than having one up top next to the ball! The whole thing is absolutely enormous; more than the description relates. I think it might be okay for giant hands, or also for tiny hands (where you can fit into the bulge of the handrest), but for normal-sized hands it's just totally wrong. The curve doesn't fit the shape of the hand, and the buttons don't go with the natural shape of the hand unless you pull back so you're no longer "cupping" the curve. This totally defeats the purpose.

Before I say anything about quality and ergonomics, let me say that when they describe this trackball as one that has a "larger, ergonomic design" they weren't kidding. This thing is HUGE. It's easily the largest trackball I've ever used. If you have large hands with sausage fingers, this is the trackball for you.

Now regarding quality, although I've only had it for a day, it seems to be built like a tank. I can easily imagine this thing lasting for years, if not decades. The buttons have a nice sturdy feel to them when pressed, and nothing feels flimsy or cheap. I've never owned an Elecom trackball before, sticking with Kensington and Logitech through the years, but I have to say that the HT1URBK seems to equal or surpass their quality in every way.

As for ergonomics, as long as you have big hands, this trackball will make you feel right at home. The buttons are comfortably laid out, and the curvature fit my palm like a glove. I couldn't have asked for better.

In my opinion, the only thing that could be better would be software support for the function buttons. While all of the standard buttons work perfectly under Linux, programming the three function buttons requires either Windows or Mac. A small problem, though, that can be overcome with a little Linux ingenuity, I'm sure.