Hey there....
Just last week we brought home our first RV...a 2006 Tioga 31M
I can't say enough about this rig..it's 31-feet in length and has 2 slide-out's. The rear bedroom slides-out with 2 windows on each side so you can see outside from the bed. In the front, you have a couch opposing the dinette: AND WE LOVE THIS. Just today we had friends over and two were sitting on the couch across from the 3 people sitting in the dinette and one person standing in the kitchen: all of us in a cirular-like area....it's like a family room and just as we'd hoped. The alternative is a typical floorplan where the couch & dinette are on the same wall and it really bisects the room.
The biggest feature, IMO, about the Class C is that is has the bunk over the cab....the kids LOVE this and gravitate to this area. You can't beat the functionality. Up front, it feels more like a typical SUV and my wife is more inclined to offer to help drive...BUT I've driven Class A's and it's really just a matter of psychologically getting past the notion that it's intimidatingly large: if you can drive a C, you can drive an A and vice-versa!
Class C's almost always come in gasoline only. There is a small RV with a Mercedes diesel and I've been warned to run from it!
As for size, we too considered just wingin' it with a 24-foot cutie....but I've been assured that once you bog-down a big V8 or V10 it's all about the same mileage. It makes sense, the frame is just a bit longer and all that framing isn't going to vary the load enough to see a marked difference between horrible and terrible mpg
Class A's come in both gas & diesel. A diesel will get better mpg, last about a half-million miles and is almost uneffected by weight...diesels simply proclaim "yeah, bring the load...I've got more torque n' power then Vegas has hookers"
BUT, with the diesel comes a higher purchase price and when repairs call, expect to pay heavily!
If you have a family and want the bunk, you can't beat a Class C. We used our friends triple-slide 39-foot Class A with all the bells n' whistles...and while it had a washer/dryer, central vac and exterior TV and other bling...we are actually happer in our Class C.
The 31M is well designed, the passage way to the rear offers privacy in that people in front can't see into the back. The bathroom has the toilet & shower in the corners, giving you room. Hate to say it, but that 39-foot Class A still has a closet-bathroom and I felt coffin-confined while using the toilet (doesn't help that I'm built like a line-backer).
That said, if you don't need the bunk, GO FOR THE CLASS A...and this is coming from a guy who owns a Class C. Why? Because there is more value!! I've been shopping hard and even had access to the auctions. I can't explain it or understand it...but there are better deals on Class A's right now.....plus Class A's almost always come with levelers, more storage, back-up cameras and other additional features.
Btw, I'm adding hydraulic levelers this week to my 31M....some HWH brand levelers, the only brand my local shop recommends. Cost? Almost $5,000 so if you like level, factor that into your decision! And you don't think level is important until you try to sleep and the bed is turning!!!!!! (I've got inner ear issues, long story).
The Class A's have bigger tires and roll nicer. The Class A's have bigger frames too. Yeah, they weigh a fair amount more but pretty much get the same sucky mpg as the C's
Neither one is right or wrong, it's just preference and what suits you. I have 3 kids and the bunk screamed tree-house: SOLD