Yeah but Bu5ter's car hasn't scratched the surface of what it is capable of doing, if you toned it down alot you could still have a 400rwkw motor that peaks at 7,000rpm.
There are a million threads about the oil issues RB's have, I think the unmodified RB30 would be excacerbated by the fact it runs 2 large supplies to the head, the RB26 unmodified has 1 blocked off. But again this is all covered in a alot of threads already on SAU.
A good example of RB25 to 30 is 88sil's car (Mark) - the 20Ghad full boost under 3,000rpm (was it 2,500?) and was all over by 6,500rpm. On an RB25 it's more like full boost at 4k, all over by 7500. Hang on will dig up dyno graphs.