You fill up all the space you're given, so why not think about use; towing, parking, weight and how you live. If space is a big deal a fifth wheel trailer is a choice.
I think of the 27' as a front bed version of the 28'. From 2012 there are two 25's, front bed or rear bed. There are a zillion threads on front vs rear bed and it all comes down to "I like . . .".
The question is really not solvable with an adding machine, it's about personal preference and everyone is different. Best to go and try them on, see how they feel.