there's a lot more to it some of which is #1 - nostelgia (yeah i know i got it too) #2 the opening angle of the o/u is greater causing it to be reloaded slower #3 the sxs has a better balance #4 doubles are usually considered DG guns and the sxs is usually more obtainable in larger calibers than is a o/u. commonly o/u's stop at 9.3x74. there's bigger ones out there but not many. There's advantages to the o/u too, such as a shotgy gun shooter who is used to his o/u finds the find it a natural and the o/u is usually available for much less cash. Thus if you have enuf for an o/u but not a sxs it becomes a great choice. I have several of both types and while i prefer the sxs, i rally can't find anything wrong with having an o/u too.