...
schild,
That's about as personal as personal questions can get. Personally, I shoulder the PG M1s90 a little bit better than the straight stock. A while back I purchased a straight stock, and although comfortable and easy to manipulate, I just preferred the PG over the straight.
A lot of folks on this board love the straight stocks whether it be on an 870, 1300, 590 or M1s90.
Try them both, and decide from there.
Sorry, that is probably as generic an answer as you'll ever get.
Jim