I can't speak on the RV side of things, but just generally for flying its REALLY nice to have that IFR capability when you need/want it. Today was the perfect example.
Planned a trip to Big Bear for breakfast, flying out of Montgomery here in San Diego, stopping at Palomar on the way. Marine layer here is very common. Flew IFR to Palomar, picked everyone up, departed IFR and canceled once above the clouds, flew VFR up to Big Bear.
Coming back, I didn't even bother to check if the marine layer had lifted. Who cares if it did? I'll just get pop-up IFR if its still there, otherwise I'll go in VFR. That bit of information will not affect my decision to leave at all. Get back, and it was gone.
I was in the clouds a grand total of MAYBE 5 minutes? Would've had to cancel an otherwise beautiful and 99% CAVU flight if it were not for the instrument capability. I do not plan on flying any real weather in my RV when I get it done, but I will have it IFR capable simply so I can blast through the marine layer.
Thats my $.02, its worth what you paid for it