The SuperSwap 1100 has a lot more to offer than the Mobile Rack. First of all, it is compatible with Serial ATA drives. That's a smart move on Promise's part because, unlike UltraATA, the Serial ATA standard already includes hot-swapping functionality. The rack is much more solidly built, to boot. The hard-drive carriers are made out of aluminum, while a fan keeps the interior temperature pleasantly cool. A small switch on the back allows you to slow down drive spin-up.
The enclosure ships with a round key to lock your hard drive down. We were also much more satisfied with the mechanism used to remove the hard drive carrier, you just have to glance at what angle the locking lever is at to know whether the hard drive has been fully pushed in or if you can remove it. The hard-drive carrier does not have any additional connectors to the swap rack; instead, you just use the SATA connectors on the hard drive when you lock it down.
As is to be expected, the SuperSwap 1100 works like a charm with the FastTrack S 150 TX2: the Windows Device Manager deactivates the drive the moment you remove the hard-drive carrier and reactivates it again just as quickly. In principle, it works much like a USB device. Only the FastTrak S150 SX4 did not recognize our test drives at all.