Years ago I used to use them quite a bit. A bit pricey, but gets the job done. However, my latest experience isn't the greatest. I own a turbo charged performance vehicle. They wanted almost a thousand dollars just to try and diagnose the issue. Without no guarantee that they will find anything. Instead of trying to fix the problem I asked to sort out, seems they are more interested in trying to get me to change the engine as a whole. Seems they have decided to follow apple's lead and make every issue, seem a big issue. Like if you have a broken button, change the whole board. I'd you have a sensor issue, change the whole board. Except what ever issue you have, you will need to change the whole engine.
Not to mention he spent alot of time on the laptop trying to find out where certain parts of the car were. In the end, I just paid for the attempt at diagnosis and flush out the oil.
Which was 300 already and then they towed back to their place and fiddled some more for another 600 for another couple hours of fiddling without finding out anything definite. However, had to pay for another oil change once again which made the oil change prior pointless except to charge more money as he already knew he was going to take it out back at their place. Seems that each oil change charged at close to about 130 dollars on top of the initial 15mins charge of 125 though they said it was going to be discounted to 85. Seems that was B.S. Then tried to pressure me to change the engine for around another 3.5k plus labour which would be at least another 1000. I said I don't need a perfect new engine. I just need it to run a few months. It doesn't have to be perfect. Just run.
In the end I just paid for all the the playing around and took my car back as it seems they are now following a script like apple does. Sorting out little individual issues is no longer their thing anymore if they think they can squeeze a new motor out of you. Funny thing is, I asked ten other machanics to diagnose and quote for the problem and it ended up costing a couple hundred for a new pressure sensor. That's it. Very disappointed and a very costly disappointing experience.
I truly believe they thought they could squeeze as much as possibe as when speaking, they mentioned what they COULD CHECK to see could be the problem, and the sensor came up, but then he got the idea of changing my engine and didn't look into that or any of the other common issues like the sensor and pump and instead was trying to find things to persuade me to change the engine.