I load on a Lee Pro 1000, and the biggest problem I would run into was the shellplate getting out of time and primers tipping and then having to clean up spilled powder, try to reset the shellplate timing and clean up the primer situation and remove the cases that were being processed and start a fresh case. I bought a Lee universal decapping die and a hand primer and now prime off the press. I've also purchased a FART and can now have nice clean primer pockets as well since I tumble after decapping. I'm now perfectly happy with the Lee Pro 1000 since I only load for hand guns currently so I'm fine with only 3 places for dies. I'm curious who primes on and off press and, what type of press people are using to see which ones are more prone to priming issues. The Mods have added "both" so feel free to change your vote.