The how it is intended to be used will dictate what the choices will be. If the intention is to do some serious traveling a unit best suited for weekending or the once a year vacation trip is not going to cut it.
If it is full or extended traveling it needs a workable galley, which means lots of working counter space otherwise there will be one unhappy cook in no time at all. It will mean a large fridge to eliminate frequent trips to the grocery, when a store may not be near by.
If doing things like bluegrass festivals, or other events where dry camping is often what it is, a unit with decent water capacity is needed. 60gal freshwater capacity is barely good for a few days.
Storage. Storage is needed for all that essential 'stuff' that needs to be onhand when things go wrong. There is no dashing home to get something for the fulltimer or extended traveler.
Defining the 'must haves' narrows the choices real fast.