Like alot of you, I bought this because the Logitech Trackman is no longer being manufactured. I own the Logitech wireless M570, but I like the wired trackballs in certain circumstances.

I bought the Sanwa Supply Trackball USB MA-TB39R on Amazon, then saw this Elecom trackball which was a little smaller so I bought it and am trying it out on my Anewish Android TV Box [ Worked Fine], My Ubuntu Linux 14.04 (also Linux Peppermint OS 6 and Linux Mint 17.3) [Worked Fine], My Windows 10 [Worked Fine] Windows XP [Worked Fine after XP loaded a driver, [ Windows 7 Pro [Worked Fine]. So for now this trackball is a keeper. It IS SMALLER in the hand, more so than the Sanwa and the Elecom's buttons are closer together so you have to fit your fingers more closely on this Elecom to use it. ** The USB cord is 5 feet long, and a flexible sturdy cord.

I flipped the top switch back and leave it in that position for a slower steady pointer movement. After reading the negative reviews here, I will keep a close eye on how long this trackball works. I don't use it alot so hopefully it will last a long time.

Scroll ball is working fine, and one switched, the pointer moves at a reasonable speed. Happy with it so far. Time will tell where this goes.

This is an awesome trackball ... with a caveat, like many others I moved to this one from a Logitech trackball.
I almost feel like I should give it a one star to ensure the manufacturer sees the review - if you keep the black ball it comes with, it's horrible.
If you take that one out and replace it with the blue ball from a Logitech - it's perfect!!!
If you don't have a blue Logitech roller ball, you probably won't like it because the ball it comes with doesn't roll smoothly.

So, why did I move away from Logitech?
I had the issues many others have with double-clicking when you single-click the left mouse button and there was no way to fix it. It was super annoying when trying to use the calculator on the computer because it would double click numbers all of the time. It would also double-click when selecting files to save, making me have to cancel and re-start the process so I didn't accidentally save over something else.

BTW ... the Low/High switch on the top of the mouse ... for me Low is normal, and High makes the pointer crazy sensitive and it jerks everywhere with any tiny movement.
My son thinks it's hilarious to change it on me though.

I've been using this type of trackball for more than 15 years, starting with the original mechanical TrackMan, TrackMan Marble, and the TrackMan Wheel. I have a couple of M570s that I use with laptops, but they are not the best for a stationary workstation and they are not as smooth as the old TrackMan even after years of use. I get RSI in my wrist when using a mouse for more than an hour or two. These have always worked great.

I had high hopes for this trackball, but I went back to my TrackMan Wheel after a day or two. The main issue for me is that it is just too small for my hand. If it was about 10% larger it would fill my hand more like the TrackMan Wheel does. The button spacing is also a bit tight. That said, the overall hand posture is right for me and the track ball is nice and smooth. I also really like the feel of the scroll wheel: it is much better than any of the Logitech scroll wheels. I use it mainly with Linux and don't bother mapping any of the extra functions. My KVM also does not like it at all, but that it also the case with other fancy gaming mice.

All that said, I am using it now after my TrackMan Wheel started acting up. After a week or two, I was able to get used to the small size. This would be a great track ball if it were a bit bigger. In the picture, the front of each are lined up to show the difference in size.

It's a good trackball comfortable left handed wireless and no perceptible lag from it either I have wired right hand Elecom trackball as well it's every bit as good just w/o the wire. One thing about both however is the software could stand to be better. The tilt wheel for left and right along with the ring finger button you cannot key bind for games. The arbitrary key and the gesture function do not work for games either all of which is unfortunate and disappointing.Gestures also don't really work in games either. What is great on the other hand however is you can use a left/right trackball together if you wish on the same PC.

I have only use in my left arm from motorcycle accident, so i bought these to see is best for me:
WishLotus® Wireless Ergonomic Mouse High-end Left...
ELECOM Left-handed Wireless track ball mouse 6...

Wishlotus good for lefty gaming, StarCraft WarCraft., easy on wrist pain, regular mouses gets painful from long uses
ELECOM comfortable, thumb mouse is easy to use but need time getting use to, i use it for browsing, the thumb mouse makes it easy to scroll around a website without moving the mouse anywhere.

BOTH have important buttons to use depending on the purpose of it, gaming i use the Wishlotus, Websurfing i use the ELECOM. Allin all I'm keeping both
I was going to return one to see what is best for me, but needed up keeping both.

*Update* WISHLOTUS the thumb button don't work on Mac (1 star deducted)
ELECOM is winning

*Update* 11/2/17
The ELECOM keeps shutting off at least once a month, its works again when i take batteries out for a day, hassle, so not worth it, it worked fine first year then downhill it went, tried reaching them but no response, so screw you and your mother.

The Wish out did the Elecom