Right now I have Z1 Stage 1 turbos, but I really have never liked them. Ive contemplated getting a new set and selling these, but I really dont knwo what I would get...Ive considered Sport 500s and Sport 530s...Id LOVE to get Sport 530's but dont want to pay the price and Im not sure upgrading to 500s is worth it...Get a bit more spool and have to probably lose $1k to do it.... =\