I also have two 36GB Raptors configured in a RAID 0, and they are most certainly fast. I'm buying another two 36GB ones for my next AMD machine because I love their performance so much.
However, data transfer benchmarks aren't realistic data transfer rates. I know for a fact that I'll never see 183MB/sec data rates outside of a benchmarking program, ever. Read this
for a competetive comparison.
I still love the speed increase they offer though.