I've got a 2004 Class C (Bigfoot) with the V10 Triton. It's been fine - reliable and powerful. My camper is on my F350 with Diesel but it's not a fair comparison because it's way too much truck for the weight of NL camper.
However, I can't say that I get back into my Bigfoot and feel like it's under-powered. Ford built me a great gas engine. no complaints.
Personally, I'd pick the RV I wanted for layout, size, etc. and just make sure you get enough engine for that. Fuel type would be secondary to me.
JMHO!
Bill