ROI is EXACTLY the driving factor... How long do you plan to stay in the house, etc. In most cases people sell their houses before they break even. Hence, I am not a fan.
Not to mention unless your roof was just done you will probably have to do it during the lifespan of the solar panels which means you need to find a roofing contractor that also is comfortable with removing and installing panels, or you have to get two contractors.
If you lease you save money on your bill, but at the end of the lease you are in the same position and do not have any added equity as the leasing option does not add value to your home. Also, if you do end up selling now your market to sell to is fewer as the potential home buyer will have to take over your lease, if that is something they want to do.
My rough math came up with a 12 year loan at 5% interest will cost about $40k for the system. Over the life of the panels there is a lot of potential savings and that savings would pay for a new system at the end of the panel life, but that also assumes electric rates will continue to rise at the rate they are over the next 25 years, which I do not think will happen.
Supply rates in CT were double what they are today 10 years ago, but delivery rates were less. There will have to be a breaking point otherwise everybody will look for alternative options. Which also means the price for alternative options will drop. Solar and wind farms are going in all over the country and the power plants are the ones utilizing them. This should in theory bring energy costs down but a lot of these solar companies will tell you that electric rates will continue to rise at a rate greater than 5% every year with no end in sight.