Depends a little on the fifth wheel you get, as well. If it's an older one, with square front corners, clearance with the cab is a bigger issue, and the long bed will make things much easier. If it's a newer one, with more rounded corners, that's much less of a problem.
I've got a short bed Ram, and I've never had a problem with my Sabre. I don't even have a slider. I'm sure that would be a different story with some other fivers, but my particular combo works well.
You've got the pros and cons down perfectly. Long bed will almost always be easier to tow with. Just a matter if you can live with it as a daily driver, and that is something that's different for every individual. For me, it came solely down to the fact that a long bed CC wouldn't fit in my garage. Otherwise the longer bed would be handy.
