I have an older Prime with the 3D 10.5 Uni Pivot and I like it.
Some folks have issue with the uni pivot but I have no problems and I switch carts every couple of weeks. I think it tracks great. For me, the anti-skate is easy also. VTF on the fly is also a good feature if you're into that.
I use a Modwright PH9.0XT phono stage and currently running a vintage Sumiko Talisman S.