zdrives are totaly scale pimp if you have the right thickness to your wallet! imo, they are hands down winners!

But, for me on a tight budget, as we all seem to be these days, I like the RCMK engine line because of the raw hp/lbs^ft to price ratio. and also the fact that u can get a rcmk k30 with rear exhaust which would totaly make pluming easyer...imo...