Going to RV show- what to specifically look for in a TT?

Thanks. I'm working on a list now. Saving a whole pile of online brochures too. I'll make a spreadsheet with the model names and start with GVWR, size, and main features.

I'm thinking I want a well insulated, enclosed underbelly model if I plan to do some winter camping. The Forest River Flagstaff micro-lite, and their higher end wildwood heritage glen both have insulated and enclosed underbellies.