Well, with that hard drive, you have no idea what chipset they're using, but it's probably a cheap one. You also have no idea what actual hard drive is in it, but again it's probably a cheap one. You also only get a one-year warranty, and the price is $190.
A
Seagate drive costs $120 on Newegg. A generic FW400/USB 2.0 enclosure using the Oxford chipset can be had for
$60, bringing your total to $180, ten dollars cheaper than the Iomega! Not bad. For $20 more, you can get a slick
OWC enclosure that is fanless, dead-silent, and matches your Mac Pro more closely than anything else I've seen. For $10 more than that, you can get
FireWire 800 too, and your total is still only $20 more than the Iomega. Oh, and you get Seagate's 5-year warranty this way. It's a no-brainer, in my opinion.