Lubed rollers, guides, and chains; replaced light sockets as requested; adjusted downforce as requested.
Contacted them over the weekend via online appointment form. Received a callback Monday morning. Was able to get work done the following day. Organized and courteous. 10% off for using online form. On the one hand, they did nothing particularly technical that you can't learn from watching YouTube videos. On the other hand, since I have never had my doors professionally serviced in 8 years, I thought it would be worth the expense to have a pro at least eyeball the equipment for my peace of mind. I thought they might gouge me on the replacement sockets, but nope: about what I'd pay if I had ordered them myself. No extra labor charge. Highly recommended.