Setup couldn't have possibly been easier. We installed the Drobo Dashboard (a three minute + reboot ordeal), slammed our HDDs into the device, plugged a single Ethernet cable from the Drobo FS to our WLAN router and powered 'er up. Drobo Dashboard recognized that a device was connected, and from there we were able to establish various Shares (we stuck with one main one, but adding 'em isn't tough) and enable Time Machine with a single click. We should note here, however, that once you set a size for a given Share, you'll have to reformat everything and start over if you want to adjust that larger or smaller. Moving on, we launched the Time Machine app within Snow Leopard (and Leopard, on a separate machine) and it immediately recognized our recently mounted Share and asked if we wanted to establish a backup there. Naturally, we slammed the confirmation button and sat back as 150GB here, 400GB here, and 128GB here were all transferred over from various Macs. We'd recommend making the initial transfer via a wired connection to prevent any tears from potential WiFi dropouts, but after that, AirPort updates were made in the background without us even knowing.
For those concerned about potential Time Capsule reliability, or those in need of something more scalable or more redundant, the Drobo FS is hard to overlook for Mac users. It's a pricey piece of equipment, sure, but the execution of Time Machine integration is downright flawless.