I'll tell you what corey - you just proved my suspicion. I also have an MTM rest. I've always shot off a 3' x 4' folding table using and adjustable front rest with a sand bag and sandbags for the rear and shot well. I thought the MTM would be a neater, one-piece solution to carrying that 5 gallon bucket of sandbags.
When I started using it I was wondering why my groups were so large - particularly from my normally tack driving rifles. I went back to shooting off the sandbags and back to shooting normally. I only use my MTM as a rest to hold my guns for cleaning or whatever. It mostly collect dust in my reloading room because I usually use my Caldwell gun vise for cleaning or working on my guns.