I think you could ask 100 of us and we'd all answer differently. Honestly, it's something you'll have to learn for yourself. My '32 motorhome is just fine for me, but I would not want to share that space with another person. My slides are also very nice to have and makes it feel less like an RV and more like a home. Some people get by on 20', and I guess I could. But I think my motorhome is just about right for me. It gives me a separate bedroom and living/kitchen area, and that's a plus as well.
Washington DC Area (NOVA)
Camper: 2004 Damon Daybreak 3285 WorkHorse 8.1
Toad: 1996 Jeep Cherokee XJ 4x4 - BlueOx
Toy: 2012 Ninja 650 - Versa Haul VH-SPORT-RO
Spent three years full time, so I know a little about it.