I actually found KK's just as fast as Mighty's. One big issue with me is ring delay, and both of these roms ring WELL before the stock sprint one. Honestly I don't like all of the programs that KK includes, but I love not having to find all the right cabs to customize the tf3d. Very satisfied with KKs, switched from Mighty's.
Oh, and here is the link to someone who did benchmarks
http://forum.ppcgeeks.com/showpost.p...8&postcount=31
Oh, and KK just put out 1.4 as well, which includes a few more performance tweaks that were not in that posts benchmarks since 1.4 just came out today.