I own one of each, I use the SBE almost exclusively for Turkeys, with the right choke and load, it will dispatch a Gobbler at unbelieveable distances,the only down side, I need to shoot a 1 1/8 oz load to function the gun every time,
it might shoot a light target load and it might not.
My M2 is a 20 gauge and it is my pick for Doves and upland
birds, it will shoot any load I can stuff in it and the recoil is
not a factor at all.
If you still have trouble deciding, do what I did and buy a matched set.