I use one place for my mot's as I know they know what they're doing, they spotted something that had been missed on two previous mots at the place I used to work at and which admittedly I'd not noticed as well. After that even when I was still working at my old job I took all my bikes to where I go now, as it was closer to where we'd moved to. There are closer places now, but still I'd go there.
My wifes MP3 though has to go somewhere they do trike mot's, it failed the other day with less than 1300 miles on because the rear wheel was wobbly, I'd not thought to check it. It was easily solved with the addition of an extra spacer between the suspension arm and the wheel. BUt you see some places still do it properly.