Been tinkering with pumps for years , especially vintage Winchester M12s
If I was to look for a new gun off the shelf today I'd be looking at saving up a few extra bucks and grabbing a Benelli Super Nova or Remington Wingmaster,
BPS is a great gun, bottom eject is nice for the lefties but wait till you have to strip it and clean it . It's tricky.
Value wise .... The Mossy covers everything , but lose the plastic safety and replace it with an after market metal safety ASAP .
Checkout canadiangunnutz.com a used older Wingmaster can be had for less then 400$
If you enjoy aftermarket parts stick with the 870 lines .
Quality is definitely an issue with all 870 expresses, but a lot of times it's nothing that some time and a dermal tool can't remedy .