Had them all, tried them all... I have 3 spheres, and sold the GTB w/ 3.5 last weekend. I naver really cared for LRP, but the spheres seem to be a lot smoother, than the violent novak. I use novak motors (13.5, 10.5,6.5, 3.5) as well, one Neo One(6.5) too.............. My unprofessional opinion