I talked with a really nice guy from Vivant about it. Honestly I'm convinced that if you plan to stay out for 20 years it will definitely be worth it.
I basically had papers in my hand to sign, when I changed my mind. The only reason I backed out is that I don't plan to stay put long term and I don't think I'd get enough money back or an increase in home value.
The tax credit was pretty good, something like 30% of the system cost, if you meet certain criteria. My system would have been for 80% production (average monthly power) and cost me $140 a month for 20 years. Now remember I would still be paying to be in the grid and an average of 20% of my power consumption. That's still pretty cheap since the power would be in the low tier price bracket. Anything I generate goes back to RMP and they credit my account. This means that after a year or so the credits would accumulate to help pay for that extra 20% of power I need in the summer months.
I also ran the numbers to go 100% solar power but it just doesn't create enough benefit for the added cost. Mine nearly doubled the amount!
Anyway, I could ramble on for another hour! Honestly it's fascinating stuff, and I'll look into it deeper down the road. If you'd like that guys contact info I can dig it up for you.