Our approach was to select the TT we thought we wanted, then we rented a similar size and floor plan.
A week or 10 day at different campsites in the Ozarks, taught us a lot about the tow vehicle, floor plan, 10 mpg, finding the right gas station entrance and exit and the overall experiences of pulling one of these barns down the road.
It definitely eliminated any buyer's remorse as we new exactly what we were getting into. We bought a used 25 ft. TT and never looked back on the decision.
Good Luck.