Funny, according to some people, we couldn't possibly be fulltiming in our 34' new gas coach. After a year and 18K miles, I couldn't disagree more. Same for the many other short gas coach fulltimers we have met over the last year. Anyway...
Here are the top things we looked for before we bought our coach:
layout: we wanted a comfortable layout that could be used with the slides in and had plenty of storage. We wanted a couch for two to lounge comfortably, a tv not in an awkward viewing position, a king size bed, and a shower a tall person could stand up in.
length: with our camping style, we wanted a shorter class A. We like state and federal parks and boondocking. Many with large coaches will state they have no problem finding spots for a 40'+ coach; they either reserve way in advance or do not go anywhere we do. Many of the campgrounds we frequent don't even have roads that will accommodate a 40' rig. Know in advance how you will be camping and buy accordingly.
weight capacity: we wanted a rig that had plenty of cargo capacity. Before we purchased, we looked at the only diesel in our preferred length and the cargo capacity was significantly less than what we got. We wouldn't go with any less than what we have, around 2500 lbs. And we still have space and weight to store more.
water: we wanted large enough tanks to boondock for a while with the ability to gravity feed the tank.
tow capacity: we wanted a 5K hitch to tow our Jeep which weighs about 4K.
If we had to do it all over again, after fulltiming for a year and going 18K miles, including Alaska, we would still buy the coach we have. It fits us perfectly. There is only one thing we would change with this coach - get rid of the carpet.
We are very happy with the Ford engine. It has pulled us up and down grades up to 12% (some of them mud and/or gravel). While it may get loud sometimes, we spend more time with the engine off than we do with it on and on highways, it is no louder than an F250 diesel (our previous vehicle).
When we purchased, in August of last year, the new model year was coming out. Dealers were making deals to get older inventory off the lots. Fleetwood was offering a rebate. We emailed a dozen dealers and took the second lowest offer - 35% off of MSRP. The first lowest offer was from a dealer with a very bad reputation for warranty work. The offers we received varied as much as $28K ($95K - $123K) for the same rig with the exact same options.
Good luck in your search. We went from an F250 diesel and a tt, to a class A. We didn't think we would love the class A as much as we do. Now we would never go back.