I own the same Samsung drive, it's very quiet, I can't hear it seeking inside my Sonata (everything else in my system is very quiet as well, pretty much inaudible in the day). I personally can't compare it to the current Seagate offerings, but the guys over at SilentPCReview that have used both all say the Samsung is quieter then the Seagate 7200.7's, and about the same noise level as the older, slower, and discontinued Barricuda IV's.
They aren't the fastest drives as already mentioned, but I'm not sure you'd really notice much of a difference between the current generation of 7200 rpm drives outside of benchmarks.
I've only had my drive for three months, but no problems (yet!).