You're looking at 2 very different guns ...in terms of Fit / sight plane etc.../ but the drop at comb, drop at heel, length of pull - and how the grip area feels to you - will be very different on both guns.
Both Beretta and Browning will give you the most gun for your money...so stay within one of those mfg's lines of guns. If the Berettas fit you - then the Browning will not...or vice versa...because they have different feels and dimensions on their guns.
The SXS is just a different animal ...because your sight picture is different vs an O/U....not that it can't work / but most of us long ago went to O/U's because of the stacked barrel concept.
Both Beretta and Browning have a lot of guns ...and I don't how you arrived at these 2 models / but I suggest you go look at a lot of guns in both mfg's lines ..and get some idea what is out there ....and then shoot as many guns as you can ...talk to guys at gunclubs, etc...
Personally, my primary Skeet, Sporing Clays and upland bird gun ...is a Browning Citori XS Skeet with an adjustable comb and 30" barrels...its available in both 12 and 20ga....for around $ 3,200 new. I think its a gun that will "Fit" 99.9% of the shooters out there because it has an adjustable parallel comb...and to me, its one of the best long term and most versatile guns in that price range. In the 20ga version its about 7.5 lbs and the 12ga is about 8.25 lbs...and personally I like my "all around" gun to be right at 8.5 lbs.../ but you might like 7.5 ...or whatever...
But before you buy - you need to spend a lot more time around some of these shotguns...your buddies are on the other extreme...with field grade 870 pumps .../ not that those don't work fine, if they fit .....but if you want a good solid pump gun then look at the Browning BPS Hunter model - a more solid and smoother gun than the 870's in my opinion.