My Wife and I also went with Sunrun, through Costco, (because we purchased through Costco we got a $2100 cash card), The "No Upfront Cost" claim is 100% true. We purchased our system, and yes, they were more expensive, but the Customer Service has been stellar. We have a 9.45kW system with 2 Powerwalls. I now wish, with summer now coming, that we had a 3rd Powerwall.
The rep explained everything to us and calculated what we needed from one year of bills. When the site inspector came he determined that we needed a new roof, so Sunrun contracted a local roofer and had a lift and relay repair done! They even subsidized $4k of the $6k bill!
Our system has the Enphase Microinverters and combiner. They located our Powerwalls outside on the East side of the house because they could not put them in the garage due to our bedroom being above the garage.
I highly recommend Sunrun over Tesla, mainly due to their Customer Service.