So would you go with a built in propane generator today?

After having ours for a year now, I would say yes. The sticker shock of the built in option would make me consider other possibilities especially since we have a Yamaha 3000 with boost. When we found our camper it was factory installed and now we find it very convenient.
Also with 2 large propane tanks, consumption isn't a measurable factor so far with just microwave and needs of my wife.