1 - The Raptors are the fastest for access/read times .. period. Several reviews, to include here at TH confirm that a 2.9ms time is still faster than the 8.2ms timing for Seagates.
2 - Icy has a point. Get a Raptor if you feel it necessary for the OS and gaming access times. This is the only reason I got one. That and the $50 rebate was too tempting. But if you go this route, be sure to get the 16MB cache versions, the 8MB versions can be solidly beat by the Seagates. Also, turn off the NCQ for faster times - the NCQ only improves multiple program access, making it a more fluid ramp up as more points attempt to access the discs. Get a Seagate with perpendicular data for storage.
3 - You wont see much of an increase by use of the Raptor if you play a game that accesses from the Optical drives. The only improvement is for HDD based applications.
Are Raptors overpriced? Yes
Do they live up to the Hype? Yes
Is it worth it? Up to you, mate. In the end, I believe the max increase for any program on a Raptor is around 8-10%, but usually lower than that.