I did some research on the two, contrary to popular belief the extra 2800 rpm available on the raptor drives still beats all of the features you'll recieve on a seagate 7200.9 series drive. Now when you're talking about a performance gain measure in seconds or fractions of seconds will you notice a difference? Maybe, Maybe not. But over time it all adds up.
Speed? Raptor.
Storage? ... take your pick, I'd reccomend Seagate.
See For Yourself
As for the difference between the 36gb and 74gb raptor drives, I do believe there are some changes that have occured between the two, but I can't say for sure how that will change thier performance.