As you can see from the responses, there is no perfect answer for everyone! You have to see how you use your RV. I have both - with and without. My 2004 RV came with a generator and we almost NEVER use it. My NL camper came with solar, but no generator. I keep thinking that I need to add a generator, but so far an inverter has covered all my needs for the few times I need more than 12v battery, e.g. microwave and TV - neither a necessity, but espresso maker = necessity. :-))
I'd travel without it and just find out for yourself. If you're a park-to-park traveler like us, you'll find it convenient but not necessary.
Good luck!
Bill