Having the screws too tight to hold the primer tube will cause problems feeding primers. Any junk from de-priming near the shuttle bar can do the same. I keep either air and/or a brush handy to keep that area clear.
After a while you will feel the difference when seating primers. I don't seat them all that fast and can tell just by feel if I missed a primer. There is a learning curve to everything new. Make sure the door for the spent primers is closed when the ram goes up. This will reduce but not eliminate junk falling down to the shuttle area.
I'm quite happy with mine as well.