it really comes down to what you need electricity for.
If you plan to camp at lower elevations, love your AC, and cannot cook without a microwave oven, then a generator is what you need. If you are fine with no AC, plan to BBQ your food and only need to recharge small electronics, then solar is the way to go.
I have used both options, for long and short trip, but rarely use the AC. A generator is great to produce a lot of power quickly, but it's noisy, heavy, can take a lot of space and good ones tend to be expensive. Solar panel are light and once they are on your roof, you just forget them. They will produce everyday, all day, and cost next to nothing in maintenance. They won't run your AC though. But they are fine to recharge the camper battery and run small appliances. The cost of solar has dropped a lot lately, and you can get a couple of good panel, with a charge controller, for less than half of what a honda generator will cost you.
My first solar install, cost me 200$. 2 panel from harbour freight, 15w, 1 amp each, controller and wire, roof bracket. 2 h to install. These little panel would recharge the battery on an average day, and allowed the kids to plug in their tablets.
one more thing: if you do not have LED lights in your camper, invest in some replacement LED light bulb. Best investment ever!