I was meaning to comment on this, as I too grabbed one of these drives last weekend. Since Frys carried them, I figured I could try it, and return it if it didn't work out. After having it installed for 2 hours, it stayed in the keeper status. It was a huge upgrade over the stock hard drive, and was only a little bit behind my Intel 40GB SSD when loading a demanding game. The old stock drive was twice as slow as the Momentus XT with the same test, even when I had the drive in my Mac Pro instead of the MacBook Pro. Once I was done testing, I ended up cloning the old drive to the new. Conveniently they were the exact same size down to the byte, so I opted for the exact clone option, instead of having to muck with cloning both an OS X and Windows partition.

A friend of mine saw the difference, and decided to go with it for his desktop instead of going for the pricier Velociraptor or even pricier SSD. This drive should hold us both over until SSDs start coming down even more.

Oh, and Mark, ended up using your recommendation of just using "cp" to clone the disk. The downside (on OS X at least) is sending a kill -INFO to cp doesn't produce a useful status indicator. dd when sent a kill -INFO will show the block it's currently on and overall stats making it a little easier to estimate time remaining. Took 29 hours to clone 500GB, mostly due to the slow SATA->USB enclosure I had the old drive in.