We've had a Georgetown 280 for 3 years. It's less than 30' long and has 2 slides. We've been on 2 extended trips of a month each and usually camp no less than 4 nights when we do short runs. It's an "entry level"...whatever... it gets the job done.
We have 2 boxers that share the bus with us and all 4 of us have enough room. We don't sit in it all day but are out and about in the Jeep or hiking or sitting outside or something or other outdoors.
We've been able to fit in all the campground both national and state parks that we want to. As Captain Happy said, you are sometimes limited because of the length of your rig.
The ONLY thing I wish was different is the arrangement of the bedroom. I wish there was room enough on both sides of the bed to have small night stands to set stuff on. One side has a "shelf" along the side of the bed that is handy for DH's cPAP but there is nothing on the other side.
We have a decent sized bath area which includes a shower with room enough to shower in. There is enough cabinet/closet space inside for everything we need which includes all the extra stuff for the dogs. The outside storage is adequate.
Think about how you'll use the Class A. Will you spend most of your time outdoors and use it to sleep in (that's us!)? If you do a lot of cooking inside, then you may want to have more counter space. I do most of our cooking outdoors. If watching TV is important to you, look for the placement of the TV and seating.
IMO, bigger is not necessarily better. The floor plan is the most important thing. The bigger the unit, the more cra... UMMM..stuff you'll cram in.