The Raptor drives certainly are the fastest SATA drives you can buy, but the performance margin over a fast 7200 RPM such as the Hitachi 7K500 is pretty minimal. In the performance tests you linked to (e.g. StorageReview) the Raptor had an advantage of 12-21% in single user benchmarks. Since the HDD is just one part of overall system performance, that likely translates into substantially less than 10% overall performance increase as seen by the end user, which is small enough that in most circumstances it is at or below the threshold that a human can reliably detect.
What that means is that other than running a benchmark or doing something that is very IO intensive (and in which the HDD is the performance bottleneck, not RAM, CPU, memory aperture, etc.) a typical person sitting in front of two otherwise identical systems, one with a Hitachi 7K500 and the other with a Raptor X, most people could not tell you which was which. As an example the performance increase for a CPU before people can perceive a difference is over 20% (with apologies to all those people who get so excited when their overclocked systems score 12% higher on benchmarks).
Bottom line - it can’t hurt to use the Raptor, as it’s an excellent drive and appears to be very reliable. Just don’t get caught up in the comments above. It’s unlikely that most people, including gamer and power users, will notice much (if any) difference moving from a fast 7200 to a 10K drive, and the likelyhood that the difference will be “dramatic” is vanishingly small. So why do people post comments like that? Look up “confirmation bias” on Wikipedia - people want to believe that their choices have had a very positive effect (the mechanism is not unlike the placebo effect).