I recently had quite a bit of trouble with those Seagates when I needed new HDDs for my system. Perhaps it had to do with the drives not playing nice with my motherboard's chipset (nF4 SLI x16), but the drives generated a TON of Event ID 51 paging fault errors on my system, making the system lag and drag horribly.
I researched the problem and tried myriad fixes (disabling CNQ, read/write caching, changing chipset drivers), but nothing worked. It was a huge frustration.
Event ID 51 paging fault errors are quite common with certain Seagate and Maxtor drives, for whatever reason, and the real kicker is that nobody (not Seagate, not the chipset designers, not anyone) is owning up to what's causing the problems. My research revealed that the problem has been in existence for several years and is NOT chipset specific, but is somewhat specific to Seagates and some Maxtors.
I replaced the Seagate 7200.11 500GB HDDs with WD5000AAKSs, and have had zero problems.
Hope this helps you make a good decision.