After a bit of searching, I finally found one place with a good variety of benchmark results: http://www.hardforum.com/showthread.php?t=1313337
(interesting thread number too )
Personally, I wouldn't recommend putting the money towards another Raptor. Judging from a quick look at eBay and Google, it looks like a new 150GB Raptor would run you around $120-165; around what a 150GB Velociraptor costs. Depending on your budget, I would recommend getting a 150 or 300GB Velociraptor to start with, and you can always RAID in another later if you want to. The 300 is actually only ~$50 more than the 150 on NewEgg, and at that price-point, a >30% price increase for a 100% capacity increase is more than worth it, if you can afford it.