I'm collecting from LAS and dropping at SLC, have a small suv booked currently, but doing a lot of driving, grand canyon, Moab and Yellowstone, so debating whether to switch to a 'sedan'...

I know its subjective but just wondering if there are certain cars that are better than others ie spec, performance etc and what to avoid too?

Oh and i have joined Hertz Gold membership, no idea how it works. just used turned up in the past and taken what was offered...In the UK they just give you x car, no options whatsoever.