In my area, Missouri, Solar City has contracted with a nationwide company,
Mr. Electric, to do the HPC installs for them. I had my appointment with the local Mr.Electric dealer today. All in all it was a good experience. They're very professional right down to uniform, their own little "Mr. Electric" door mat, booties/shoe covers. Ironically, those sorts of things put me on edge--had a bad experience with Benjamin Franklin plumbers once and they do a similar thing...must be Post-traumatic stress disorder!
That said, their rep, Nathaneal, was very polite, professional and knowledgeable. SolarCity has not just abdicated the installs to Mr.Electric, they have specific pricing guidelines, insist on photos of all the various locations, the meter, breaker box, the house itself, etc. They have a specific form/questionnaire that needs to be filled out, etc. Ultimately I did have the feeling of confidence that he knew what he was doing and thought his ideas for how to do the installation were good, and probably better than my 2 prior estimates (mainly he's wanting to change my meter out and run a dedicated line to a sub-panel in the garage whereas the other guys were just going to run power off my existing 200amp panel.
When looking at the SolarCity preset prices he couldn't find anything that quite matched my unique situation, but taking the various options into account roughly estimated $3000 for the install. That's $1000 (50%) more than my other two estimates! He wants to meet up again next week with a more detailed breakdown and price, I think he's going to try to come down somewhat, but it's going to have to be quite a bit for me to go with them. I'm willing to pay a small premium over my other estimates as it's clear that there's an emphasis on installing to code and doing an extremely professional job, something I'm not sure will be quite as good from my other estimates, but I can't justify an extra $1000.