Need Input from you guys

The main thing I hear about is just poor performance over all...Obviouslly the people who built them didnt have a clue as to what they were doing.....My freind that has one has had good results though he spanks me every time we run....If your gonna build it or have someone build it just make sure they know what there doing see if they have other kats they built them for and find out if they were happy......