Pros: I have 3 of these, and I'm really happy with them. They make it a lot easier to replace drives, and they let you fit more drives into a smaller space. In addition, they provide delayed spin-up for your SATA devices. It's undocumented in the manual, but drives don't start spinning until they're scanned by the BIOS, while the same drives start spinning at power-on if they're not in the enclosure. That saves me ~30A of 12V power, which means that I can get by with a 750W power supply instead of needing 1k or something crazy like that for a 18-drive system.

Cons: It's a pain to fit into any case with shelves for 5.25" devices. I've had to dremel off a couple to make it fit. That's not supermicro's fault, though.

Pros: Using it to hold a 27" monitor plus a 22" pen display. They easily move from side-to-side to up-and-down, with the pen monitor in a convenient drawing position. Looks good, seems solid, easy to assemble.

Cons: Nothing comes to mind.