my observation:
If you use the exact same pickup to tow a TT as you would a 5ver , there is no problem . the equivalent TT will be lighter and lower .
too many folks pull a travel trailer with a half ton when they should use a 3 /4 ton pickup.
with a 3 /4 ton pickup ( the same PAYLOAD as you would REQUIRE with a 5th wheel ) it is possible to eliminate sway with a TT .
Heavy tongue weight percentage eliminates sway .
Pickup payload capacity ( with a reserve ) must be adequate to add 13 -16 % tongue weight .
we use a lockable snugtop canopy on our short box duramax .
we carry heavy stuff in the pickup bed such as : cooler full of cold pop , boxed plywood scraps and duraflame logs , two EZ-UP Quik Shade canopies , a propane tank to run our bbq , an extra 5 gallons of fresh water , and so forth .
what really works well for us is a 9200# GVW pickup towing a 7200 # (axle ) GVW travel trailer .
for a long ( non hookups ) camping trip we will often be 8600 # in the pickup and 5600# on the trailer axles .
here is a shock ! the trailer does not wag the tow vehicle .
simple physics .
to change to a fifth wheel i would lose the versatility of the locking canopy .
half tons have much smaller brakes , smaller driveline capacity , and smaller frames. go to a tire store and compare them on the rack .