Went from MWB (5.5mt) Sprinter Campervan & VW Golf to a SWB T5.1, 7 years ago.
Predictable positives and negatives:
Positives; One set of bills when I was quite skint. Only one vehicle to worry about. T5 is fine as a replacement for the golf. Works fine as a campervan for just me and my dog. Much easier to tour in as can park anywhere.
Negatives; miss the shower and loo, oven, bike storage, being able to get up and walk around the van on a shitty day. Tend to use campsites more often.
Due to stuff going on T5 has not had heavy campervan use in last few years, but that has changed since retired to Scotland. Thought about replacement with a Crafter earlier this year. Decided to refresh the T5 (new lithium, extra cupboards, porta-potty) and use it for longer periods away whilst I think about what I want. The T5 only has 45k miles on it so its still a young vehicle despite being 12 years old.