In my case, I needed to fit two SSD's in a single 3.5" bay in a small server. The SATA and power cables are already provided and come from a RAID controller. With this adapter, the two SSD's are too close together to use existing (combined) SATA/power connectors. In a more typical setup where you can use the included cables, that would not be a problem.

The other issue I had was, with two SSD's installed and with the whole assembly snapped into the Dell drive carrier, the carrier was uneven due to flex in the adapter. With a normal 3.5" drive in the carrier, everything is straight. With this in the carrier, it isn't straight and won't slide into the bay.

All in all, this adapter has it's uses and works in some scenarios, but it not a universal adapter.

I have a couple of these and am always looking for well-designed systems that only need my fingers as tools. The SSD's or similar sized drives just snap into place and are removed by moving a spring loaded button that is pretty easy to figure out.
I am giving the basic design 5 stars and am knocking it down a star because my particular setups (HP Z210 workstations) require 90 degree connectors for both the power and data connectors. I am still looking for a connectors that will work when the drives are so close together. I ended up using one bracket for each SSD. Also some spacers would be nice as the Samsung SSDs I am using a kind of sloppy in the bracket. I wouldn't mark the product down for that, however. The brackets fit nicely into my hard drive caddies that come with the Z210s.

To be honest I'm a tad disappointed with my purchase on this product.

Pros:
Holds the designated drives fairly securely--it doesn't feel like the drives would be able to fall out.
Fairly inexpensive.
A very simple, clean appearance.
Front port allows you to use hot-swappable 3.5" drive setups.

Cons:
- The entire thing is constructed from single piece of plastic. This concerns me as to the longevity of the product.
- Terrible arrangement of drive mounting. You are unable to install 2.5" drives unless you have straight angled SATA power cables, and I don't know of many PSUs that include straight angled SATA power cables. If the 2.5" drive mounts were placed 3/4 of an inch back then this would not be an issue. Included picture reflects this.
+ A simple work-around for this issue would be to mention that a straight-angle SATA power adapter would be required when mounting 2.5" and 3.5" drives.

Other thoughts:
The spring retention for the 2.5" drives feels quite stiff when mounting the drives, and when factoring in the plastic, it results in a bit of an uncomfortable feel when mounting SSDs, which I'm sure a good number of people would use such an item for.

If you need a cheap solution for mounting a single 3.5" HDD or two 2.5" drives/SSDs, this will work as intended. Just be aware that it is made of plastic, and if you intend to use both drive sizes, you WILL need straight SATA power plugs for the 2.5" drives.

This product did exactly what it was advertised to do. Although it is made out of plastic it seems very sturdy and once you get it in the machine you won't be moving it out that much anyway. The fact that you can slide in a 2.5" drive with no screws or tools is great. It came with plenty of screws but I didn't actually need to use any of them since my case faceplate had the necessary screws already which worked just fine.

This allowed me to add 3 more drives to my Optiplex 7010 that is serving as my NAS server. With another one of these and no optical drive, I could add up to 7 drives to store data. Couldn't find a way to close the hole in the front of the device with a 3.5" drive installed so that is why I put it down to 4 stars. Since this is in a server that sits in a closet it isn't a big deal and does provide some extra air flow.

really nice product for what it is. Wish there was an all metal version that would fit mount in a 2.5" (bottom screw) installation. This works really well in a 3.5" bay, which is as intended.
Specifically, I'd like to be able to mount 6x 2.5" SSD's in a small SuperMicro Case that can normally mount 2 or 4 (with 2 supermicro cages) 2.5" HDD/SSDs. The case can alternatively hold 2x3.5" hdds, and this works well for that, but we loose the ability to use the expansion slot completely.
Also, I suspect that a metal cage would be better for heat dissipation from the installed drives. A simple bent metal, 3x7mm drive cage would be wonderful, even if that meant losing hot swap capability. a 1mm (20 Ga) thick sheet metal, properly cut drilled and bent would work great! Wish I had the metal shop and skills to build it myself!