This sounds like a fantastic product for somebody who, like me, that finds themselves constantly swapping out hard drives and SSDs like a merry-go-round and would be perfect for somebody who has a PC case with 1-2 extra 3.5 inch external bays that aren't being used. The idea of having a locking mechanism so that the drive can't easily be "bumped open" by accident is a very clever idea as well, as I can say from past experience this has happened to me once before. Thankfully I lost no data from this mistake, but sometimes just a little feature like this can go a long way towards data protection and safety precautions.
Towards all of the holiday deals during Black Friday I've been contemplating sourcing several smaller cheap SSDs and creating a RAID array involving SSDs so I could potentially take four blazing fast drives, slap them in a RAID 0, and have a RAID array that could easily approach 2 GB/sec read speeds! I haven't actually made up my mind if I'm ready to commit to purchasing 4x 120/128GB SSDs just yet but if I end up making that decision then this would be something I would definitely consider purchasing.
An all-metal construction is another feature that I feel would be of particular interest, because of course you find adapters all over the internet that can internally support 2x 2.5 inch drives but the vast majority of these brackets are of plastic nature. Speaking from past experience, these mounts with plastic holes aren't designed for longevity in mind...and I've found myself stripping the holes out of an adapter once to where I ended up having to toss the adapter in the garbage because of this. Some might argue that I over-torqued the screws when I installed the bracket, but when I install hard drives I don't typically put a lot of torque on the screws that I mount my hardware with because it can be damaging to the adapter itself as well as the drive. I actually use a special screwdriver for all of my installations that puts an even amount of torque on each screw as it's driven into it's hole so that I make sure not to over-tighten screws inside of a new build.
This sounds like an excellent product that sounds like a first for commercial-grade hardware that is available to home DIY consumers such as myself. I'll be keeping this product in mind for when/if I decide a quad-SSD RAID 0 array is something that I'm interested in!