If it came down to having a bumper pull that could fit underneath my barn or a fifth wheel that would be left out in the elements, I'd get a bumper pull hands down.
I've had both: three bumper pulls and two 5ers. I now have a 5er just because the only way you can get over 40' typically is with a 5er.
If you find a bumper pull you really like, get a quality WD hitch and HAVE IT SET UP PROPERLY. My last bumper pull was a 33' Work & Play with a 1500 lb. tongue weight. Once I set up the Equalizer hitch properly (not like the dealer did), it pulled as good as any 5er out there. Sway was never an issue; even on the interstates at 70 mph and large rigs passing by didn't phase it at all.