Just saw this thread, haven't been around in a long time. I've installed about 12-13 RV solar panel systems, usually with a battery upgrade and inverter install, plus 2 yacht solar systems with inverters and batteries.
Here's a quick rundown of some of my thoughts, based on the above and posts in this thread.
If you're going to run 700 or 800 watts or more, then you need to look into the really good MPPT controllers like Outback, Midnite Solar, Morningstar, Rogue, Magnum, Xantrex, Victron, etc.
What I don't like about most of those is they're expensive, and most of them force you to buy a remote display to see what's up, at $100 or more. You could mount say 3x300w panels and use 3 Eco Worthy controllers, about 1/2 the price of any of the above.
In Hemi Joel's case, I agree with toyhauler, he could have bought 1 250 watt panel for $148 and a 20A Eco-worthy MPPT controller for $102, spent a couple of $$ on good cable and if he was parked facing south, he'd get about 14A peaks in the winter, probably 18A peaks in the summer. Not too bad for a $275 investment. So far, I've installed 10 Eco-worthy controllers (2 for myself, 2 customers are running dual controllers) and I'm very impressed with the speed it locks onto MPPT, the easy on screen menu allowing you to set all of the voltages in .1v increments, the gold plated contacts and all SMD internal construction with conformal coating. I have one right now with 410w of panels on it and it will put out 22A (110%) all day long and doesn't miss a beat.
I'd be very careful about using semi-flexible panels, they really aren't all that flexible, since they use the same silicon based solar cells as regular panels. A few brands (Solbian, Renogy, Kingsolar, HQST, Allpowers) use Sunpower cells, which are currently the most efficient cells on the market, an important feature with limited roof area like a boat or RV. But all of them, even the Sunpower cell versions, are prone to micro cracking from flexing, and overheating due to being a very dark surface and no cooling on the back if mounted flat on the roof. Renogy recently had a recall of all of their panels and added a thin aluminum panel on the back to dissipate heat, some of the owners who removed them reported scorched fiberglass underneath the cells. I'd be concerned the adhesive and rubber roof on an RV would be a lot easier to ignite.
The other issue is the "off brand" Chinese made panels are noted for producing considerably less than the advertised 100w/panel. A lot of boaters have removed the flexible panels and switched over to rigid panels and used them to make a bimini or cover.
I also agree with the GC batteries, I usually install 4 or 6 for my RV customers. Much cheaper and more power than most deep cycle batteries. Something to keep in mind, most people never get their batteries fully charged. I'd go to the mfr's website and look up the absorption voltage they recommend. It could be as high as 14.9 or 15v, if your controller and/or battery charger is adjustable, anything less than the recommended voltage isn't going to charge them up.
Toyhauler and I are both running enough solar power (he has 750w, I have 475w) that we were going into float mode by 10 or 1030 am, so we bought ice makers (he has 2 of them) to make ice all day and keep the solar charging a bit longer, keeping the batteries in absorption mode all day and crank out ice for drinks and coolers. I know a lot of people do an energy audit and budget and all that...
but there's no such thing as too much power, or too much ice!
