I own an AA S410Classic .22 bolt action, AA S410ERB side lever .22, BSA S10 Mk3 .22 and a BSA Ultra Multishot .177 and the nice thing about all of these PCP's is they did not require any tuning whatsoever. They all shoot with pinpoint accuracy right out of the box.
The S410 side lever is by far the easiest all around to load and shoot, I prefer it over the bolt action it is really smooth.