Interesting. Here are my experiences with jamac.
1) Walked in with a pair of Fisher xp7b's to get them checked out. First ever set of vintage speakers. Ron pulled out the drivers to test them and give them all a look over. Ron pinched the speaker leads between the cabinet and speaker baskets on both 12in woofers AND left 2 screws out. I gave him this "wtf??" kind of look and he gave me his screw driver and said "if you want to nit pick do it yourself". I indicated that the leads were pinched and that I am hardly nit picking. He saw it for himself and corrected it. After everything was together he listened to every driver and said it was all good and they are ready to go. While listening to them all hooked up I noticed a tweeter was not working and I pointed it out to him. He looked at me and said "you are right, let's see if I have another one". He did and he sold it to me for six bucks. Why didn't he catch that?!?!
2) He refoamed 6 speakers for me. All came out good.
3) He recapped a crossover for me. He wanted to do it while I waited and needed my help to do it which was fine with me. In the process of removing the old caps and soldering in the new ones he melted 3 huge chunks of plastic out of the crossover bezzle. That PISSED me off although I refrained from showing it. I pointed it out and he said it does not effect performance. WTF?!?!
4) I brought him the mids out of my mach twos for refoam. He installed the wrong foam and the screws that hold the speaker in place pinch the surround. I showed it to him and he told me to silicone the speakers into place rather than screwing them down. I did not want to do that (who would?). I asked if he could redo it with the right foam and he said that's the closest foam to the correct foam he had, he refused to order in the correct foam and that the only solution he was willing to offer was to silicone the speakers into place. I refused to do that so he cut up the foam with a razor blade and gave me my money back.