Esp is the best feeling buzzz ever. It will last forever, and in a couple of years and hundred of tree hits later, it will fly like a Buzzz ss. You win!
Edit: i suggested esp because the grip is simply better than the Z plastic. Z buzzz are really stiff and can be a little slipery at time. Esp is a softer a little, but it releases really nice off the hand. I have tried z, esp and flx, and the esp takes 1st place for me.