The two that i've stuck with so far is,the NAP SmartRest, a pretty good system, BUT I HATE the "THUMP" you get after the shot with the 'Vee armstricking the rubber arrow holder".
The other rest is the TR DZ, micro adjust. However this restgives 'me' a bit more time to tune. The locking system on the windage bar could do with some changes and the twosprings on the suspension rods should be a little longer.
They are so many D/A rest now to choose from. The Muzzy works well, but it's really a hulk of a rest (for me).