Its going to be loud? I dont knoiw where you get this from(I mean they make noise but its not louder then my cpu or case fan). I have 2 320 gig seagate 7200.10 and they are awesome. The real question you have to ask yourself is how much if a freak are you about loading time for a game or startup of windows. I really didnt see shaving off a few seconds as a real reason for this. I mean, i got my 2 for a total of $180.
I don't know if it is completely true but 10,000 rpm have a tendency to break down sooner. I guess it would make sense as they spin faster but I don't know.
For me i would say the 7200 becuase i couldn;t justify the price to performance ratio.