I'll start with the basics: John is punctual, professional, quick, and very competent. I would absolutely recommend him to any of my friends and family.
On to my visit, specifically: I had an issue with some suspension work that I did earlier this year (DIY). I was having trouble tracking down the issue, so I wanted to get some professional help. This was my first time ever using a mobile mechanic service, and had never met John before. He showed up within 2 or 3 minutes of the start of the appointment window. After the usual courtesies, he got right down to business. He asked a few questions, listened me describe the work I had already done, etc. Then, he took a quick look around and made his recommendations.
I'm no mechanic myself, but I do have enough knowledge to be dangerous. I can tell you he didn't recommend anything unreasonable (no cabin air filter nonsense to run up the bill, etc.), and he definitely caught some minor screw-ups I made during my DIY adventures. We scheduled a time for him to come out and replace the parts (sway bar end-links), and parted ways.
Again, he showed up right on time. He installed the links and made a couple of minor alterations to fix my mistakes, all in about 40 minutes or so. He probably could've done it faster if I hadn't been so chatty. If I had done the work myself, it would've easily been 3 or 4 hours (optimistic estimate). It was worth it to get it done quickly and professionally, and to have a second (more experienced) set of eyes on the work I did previously.
You won't be disappointed with John. If you've never used a mobile mechanic before, you're missing out. It's a much better experience than getting an appointment at a shop, taking off work to drop your car off, finding a ride, blah, blah. John won't BS you. If he recommends a service, it's because your car needs it. He brings all the tools he needs, plus the parts he'll need for the service/repair. Unless it's one of the few things best done at a specialized shop (alignments and such), he can do it just as well as a traditional shop. Even if it wasn't cheaper, I wouldn't go back to a shop. Of course, it is cheaper, so that's nice, too.