We have a nice 24' 6" C and it is perfect for the two of us (and of course da pooch), but I just do not see anything in the 25' range working for your family of 4. Having to make up the dinette which becomes a smallish bunk at best, every night will get old fast. Coming from a large fiver you will probably need to be closer to 30 to comfortably make it work and then you are back at the "Gotta have a Toad dilemma" .... but since you asked:
Using ours for sightseeing, shopping etc., is a piece of cake as it easy to drive and park. Leaving a site merely entails putting a couple of items away, disconnecting from power (if available), turning the key and driving off. Yes you do need to keep the clutter to a minimum but that has always been our routine anyway.
Leveling has never been an issue. I use the yellow Leggo style blocks and have never needed to go more than 2 blocks high. If leveling takes more than 3 minutes and two tries I am simply not paying enough attention. Leveling systems add weight, complexity and expense but some folks like the ability to just push a button (you frequently see them under their coach placing boards for the leveling jacks to sit on). :h
Our C, like most out there, came with a 4,000 watt built in gas generator and works great. Located forward on the street side it is very quiet and fumes have never been an issue. In the last year we have put 18,000+ miles on the coach and only 25 hours on the genny. It burns about .5 of a gallon when running under a heavy load (which is the best way to run it). A propane generator will use more propane in extended applications than most coaches carry (keep in mind that an LP tank rated at 14 gallons will only hold 80%=11 gal, of that figure), gas is cheaper and easier to refuel. If your coach is a diesel then a diesel genset makes a lot of sense but LP.... not so much.
The Hershey show would be the ultimate place to look as they reportedly have everything under the sun. Bring the entire family and see what will work for all of you but I would leave the checkbook home as they have some smooooth talking salesmen there. Good luck! :B