Hi BFL13,
The reasons for going solar, in my case, were (in no particular order):
-to start each trip with the battery bank fully charged
-to extend the life span of the bank
-to optimize charging voltage at the ambient temperature
-to equalize the bank(s) on a monthly basis
-to power the trik-l-start for the chassis battery
-to provide all power when boondocking
I can, at this time of year, harvest enough solar to run my laptop all day and all night, do my cooking (3 meals) electrically on an 850 watt hot plate, and get back to 100% state of charge while not driving an inch.
I did "join the dark side" in the first week in July, and got a generator. It is used to power the air conditioner. My profession requires me to be in clients homes and as my RV is now my "main vehicle" I can not afford to go into homes smelling like a pole cat.
I would never run the generator exclusively for battery recharging, as my converter only does 40 amps--so it would be a huge waste of fuel. Of course, while running the air, I do "opportunity" charging, but that is often under ten amps. I also run the fridge, and (thanks to you) run the water heater via the inverter when running the air conditioner.
The most I've seen for straight battery charging from the alternator (i.e. not running the hot water heater) is 40 amps. The least I've seen is -8.5 amps (yes, negative amps of charging) with the solar panels sending power to the engine. My charging circuits are circuit breakered at 50 amps each. My hall effect ammeter cuts out at 70 amps.
My typical watts draw, when doing the above, is about 2300 watts (without the water heater).
I do have manual control of the solenoids so I can limit charging, if need be, to protect the alternator. I use a strategy of 5 minutes on and 5 minutes off, when running the hot water heater.
I'm still very much "feeling my way" now that I am nearly entirely full time in the RV.
