If your regular mechanic is both trusted and brilliant you should be throwing as much work as you can at him to keep him in business, and keep him familiar with your cars, so he can keep them in good shape and keep you informed about them. I do all of my own brake work, but when having some differential work on my pickup (now that's specialty work!), my mechanic said my rear shoes needed replacement, and he already had the wheels off to pull the axles, so yeah I had him do the brakes. Then we got into a discussion about the quality of rotors, he had a short list in his head about which rotors he used for which types of vehicles, he was very particular about his choices! That kind of knowledge doesn't accumulate unless the same cars and customers come back to the same mechanic repeatedly. In chain shops like Midas, the likelihood you'll get the same guy doing your brakes 3 years from now is quite low.
As others here have stated, brakes are not specialty work. It is easy bread and butter work for any shop. However some shops do them much better than others. In particular, better shops use proper lubrication, using quality components and checking runout against spec. Proper lubrication is a big deal. The factory service manuals on my cars spec different kinds of lube for the pins versus the pad backs and ears. Some shops use the same lube on both. Some pad-slap and put on no new lube. Most shops (from my personal experience) check only pin lubrication, and never lube the pad back or ears.
On my Honda you can pad-slap by only removing one of the two caliper pins and swinging the caliper up out of the way. On those brakes some mechanics never check the lube on the other pin, too easy to make more money on saving a few minutes and squeezing in another job, since they are paid book time no matter what the actual time on the job is.
Likewise runout is a big deal. Fresh components will work OK for 10K miles since the caliper floats, but the smallest bit of eccentricity on the mounted rotor (grit or rust on the hub for example) and the high spots will build up pad particles, have increased friction over the rest of the rotor surface, and you get the wubba-wubba feeling of brake shudder. Then you take it back and they blame you for warping the rotors by running them hot through a puddle.
I'm not going to beat down on Midas, how good they are varies. It depends on the local shop, and as you found out, who you get that day. We had one locally but it went out of business some years ago. Meanwhile several local guys have been expanding. That tells you something about that particular Midas shop. On the other hand, I have friends who use chain shops with good luck, they know the owner and have a relationship, and staff turnover is low at the best-run chain shops.