I installed the drive today (had to remember to get those little nubs at the ends with the torx t6 and put them on the new drive so it would sit in the rubber holder). It is a lot louder than the old one (mainly when re-installing slow leopard and reviving from my time machine backup) but for general use it isn't too noticable. It seems a tiny bit faster, but nothing really noticeable like SSD's.
The extra space is nice cause I can bump up my windows 7 partition from 20 gigs to 50 gigs and actually be able to use it, and now my mac partition is not 95% full (about 30-40% full now).
I got it on sale for just over $60 canadian (including tax and everything), and i'm not going to upgrade to an SSD until I can get a 300 gig intel SSD for about $300-400 dollars.