Be skeptical on the performance claims provided by the supplier. they make money leasing them to folks, and will give you best case ideal numbers about the money you'd save. Be skeptical on the number from other people who currently lease. Like the early hybrids, owners will stretch the truth to halp justify their own solar decision. I have no experience with leasing them, but expect there to be a lot of deceptive marketing and over hype, so I'd advise giving yourself a big margin, so that if the real world numbers don't reach the glory that you were promised, it's still worth it. Also remember to include all associated costs, such as install, set up, maintenance, etc.
Not saying don't do it, just work to get good numbers for when you calculate the costs and make the business decision before you do it.
I'm too afraid to commit since I just found out about new/newly hyped leasing option. For now, the house will be rented as is. Maybe when things get better, I'll buy-who knows.