I have the Seekins Precision on my 300 Blackout. Muzzle climb/recoil is a non factor. Doubt on the other hand? It is loud as hell! I had shot another 300 blackout without hearing protection an was fine. Tried that with mine and my ears were ringing. This thing is a sound amplifier.
I put the Spikes Dynacomp on my last build and shot it yesterday. Feels like shooting a 22lr! :-) recoil was very little. Watching my brother during rapid fire, muzzle climb almost non existent. When you are shooting gun sound is pushed out and away from shooter. Louder when standing off to the side of shooter.
Now I have stood next to someone shooting my blackout and it is loud loud and you can feel the concussion every time trigger is pulled. That is not near as bad standing next to the Dynacomp. I felt no concussion wave with it.
Now I don't have any experience with the other comps mentioned, so I really can't compare to them.