We have a 5'er after having two TT's. The nice thing about a 5'er is the front storage areas. Instead of loading all that stuff in your truck and than having to unload it when you get home, it just stays in the 5'er.
Another nice thing is you get virtually no sway when pulling a 5'er. No messing with WDH setups.
A 35' 5'er and CCLB truck will be about 52-53' OAL.
A 35' TT and CCLB truck will be about 60' OAL.
You can squeeze a 5'er into a shorter spot because you are able to back the truck under the front by splitting the 5th hitch and one side of the truck bed.
Hitching and unhitching is simpler as well. No cranking on chains or lifting bars onto brackets. No WDH sticking out from the rear of the truck. When hitched up you can walk between the 5'er and truck as opposed to climbing over the tongue or walking around the TT or truck.
5'er's as a general rule are less susceptible to winds and semis'.
It all just boils down to personal taste. Some don't have a truck big enough to haul a 5'er and choose a large TT instead.