I like windows... big windows. but make sure they have the sun shield coating on them, as the summertime sun shining thru all the windows can make it nearly impossible to cool the interior....
then, in the winter time, the windows act as heat sinks.. they absorb the heat and turn it in to cold... so it costs more to heat the unit than one with less windows.. and toy haulers arent known for having good insulation anyway.
the bigger the unit, the worse the problem is, and no matter what manufacture you talk to, they claim they have about the best insulated units in on the market..
we get about 60hrs/2.5 days of use from (2) 5gal/20lb propane cylinders in outside temps of 35-40 degrees... keeping the interior at 68-70 degrees...