I got these for my home server. I knew I was taking a bit of a chance because of the mixed reviews, but I bought one module to try out.
These units are fine, IMHO. They do what they're supposed to do, and are well made. They're not crap is what I'm trying to say.
Yes, they could possibly be stronger, but what couldn't? If you're not stupid, and handle your stuff with reasonable care anyway, you will have zero problems with these units. They're not junk and work just fine, thank you very much.
You will want to try them out in your case first, if possible. They are large and need additional depth, plus the side panel design might not be compatible with some cases. In my case, the server uses drive rails, and these bays work fine.
I bought four of these, plus one 4-in-3 bay (MB674SPF-B). I have this giant, old doublewide server case that nobody has ever been able to identify, and it has four bays on the left and ten on the right, plus some internal bays for the system drives. Now it holds 16 external hard drives, plus a DVD drive, with room to spare.
Previously, it would take me at least an hour to down the system, take it apart (yes, it is semi-toolless) insert and attach the drives, put it back together and reboot. Well, I just stuck in the last four drives and it took me 5 minutes. That, to my mind, already paid for the hot swap bays. Not to mention being able to pull a failed drive some time ago in 1 minute.
Hot swapping has been a bit iffy, but I think that's a consequence of either the Escalade 9650SE-16 or the power supply not being up to the task. Some bays appear to hot-swap fine, but there is one individual bay in one 3-in-2 dock that gives my system fits. So you may need to test out if hot-swap is really going to work. Note this is more than likely NOT the fault of the bays, it's just a consequence of running a relatively large RAID array. You can always down the server for 5 minutes to upgrade.
I picked these units - and waited six months for them to become available - because they include a nice fan, which is easy to swap out, as well as a high-temp alarm. I have never heard the alarm, and I hope I never will, and I've never changed the fans, and I hope I never will. There's always a possibility that a fan will fail, but so far the only one I've actually seen was one on a CPU cooler, after over a decade of continuous use, so I'm not too worried.
I don't have SMART data on the drives because the 3ware doesn't give it to me - not sure why. But there appears to be enough airflow to keep everything cool. I previously had all the drives in iCage units, which are great, but don't expand the drive bay capacity. I can't tell any difference between the Icy Dock and the iCage exhaust air temp.
With that many fans it's going to be noisy. But if you have an 18-drive machine in your office, you expect that. Put it in the basement already. I don't even try to regulate the fan speeds, they're all set to high permanently.
I'd recommend these to anybody looking for something like this. As a bonus, they make a large system look pretty badass in an understated way, all professional, clean and symmetrical.