Just like with cars, leasing is a personal choice and can be a good option for some, not right for others. We would have concern long term for any solar company other than Solar City. One of the reasons we leased was a hope/expectation that the company would be around to service the system should anything go wrong. In the 4 years we have had our system, we have had both inverters changed. From what I can tell, that would have been $5000+ incl labor. We have a 20 year prepaid lease, so short of out right buying the system, that was cheapest option. They also offered no down and you wind up paying the savings difference to them instead of electric company, but that would have been quite a bit more in the long run. This is likely where the PPA is pushed. We also couldn't buy and get the tax break ourselves due to not enough taxable income. Prepay also removes any issues if selling the home as the new owners wouldn't have to make payments for example.
All that said, figured most solar systems are getting cheaper by the day and most are going to want the actual roof to be the panels in the coming years instead of on top of existing roof. In north Texas, we have to change the whole roofs pretty often due to hail. The last hail didn't even phase our panels, but certainly caused damage to uncovered part of roof.