It all depends on how you like things. Going from a truck camper to anything can make the new thing seem really big. Not long after that, the new thing can seem too small.
We had an 11 foot camper on our long box extended cab Chev (22 ft) so the camper stuck out three feet farther back for 25 ft. The camper seemed very cramped to us, being used to our 28ft 5er we also had.
We had a 22 ft 5er at first, thinking it was huge compared with the 8.5 ft camper we started with. Nope. Too small. The 28ft 5er was perfect for us. Main thing is I get up early and she sleeps in, so there needs to be some room. Also we have some dogs and their kennels to keep somewhere.
We now have a 28ft Class C with no slide and it is just right. Almost as much space as the 28ft 5er and a good floor plan. We have looked at lots of smaller Cs and they just don't cut it-too small!
As far as driving it around, there hasn't been an issue. It is longer than the truck with the 11ft camper, but not much, maybe three feet. We park in mall parking lots, any provincial park campsite around here (on the Island) and at home. Goes where the 5er went in our yard. Lot shorter than the truck towing the 5er too!
So for us, no way would we want a 24 ft C, that would be as bad as the 11 ft camper in our minds, but really more like the 22 ft 5er that was too small.
It must depend on how you like to live together all day. If you like to read and she watches TV or do you both do the same things sitting next to each other a lot? Do you need some "space"? DW says she notices that people with smaller Cs bail out and sit outside as much as they can, where with a bigger rig people stay inside more. We think we know why that is.
Bottom line is don't go by your truck camper experience in judging how big the Class C or trailer is. Knowing how it went for us, I think it would be wise (20-20 hindsight) to rent a 24 ft C and get a feel for it for a two week trip. Then go sit in a 28ft C and see if you would like that a lot better or would be fine with the 24.
You take a bath on trading in and buying again, so it is better to get it right the first time. BTDT :(