Tdubya- The 5th wheel i currently have the bunk room is it's own room with door off the back. Very similar to what a toy hauler has now. So it wouldn't necessarily benefit in that way.
N-trouble- One problem is play area. Camping with little ones trying to eat stones all the time gets frustrating. I would think a side and back patio would help in that they have there area to play and can only get into what you give them. Also down the road with bikes, etc. the garage would help getting things to the campground.
I also want a toy hauler but need justification for the wife.. I really don't want to buy one then miss the bunk house and have to tell her she is right.
There is a few others things i currently don't like about my camper but most of them could be solved with a newer bunk house.