I will never bother having my gait analysed at a shop again. I've wasted so much time and money with them and much of the time the sales assistant was quoting from what they had been told not from real knowledge. After many many wrong shoes I just went out and bought the simplest, flattest shoes I could find and found running was instantly better. Then I did some proper research and ended up with Nike Frees which I have used ever since and have been injury free. A lot of shoe selling is pure hype.
3 legged pony may well be right but I too am a little sceptical.
I went to one very reputable shop in London a few years back and after `testing` was told I was an over pronator.
I was recommended shoes - ran in them for a year or so - got injured (to be honest, it`s difficult to know whether it was the shoes, the increased mileage or just bad luck) and went to another reputable shop near Cambridge.
After testing I was told I was very `neutral`. Certain (different) shoes were recommended which I wore without problems for a few months. I eventually ditched them simply coz they were too heavy.
Over the last 2 years I`ve moved towards lighter shoes and now train, very happily, in racing flats.
I suppose much depends on the experience and expertise of the individual doing the testing.
I think, on balance, it probably is worth going to a running specialist shop for assessment.
Having said that - there is an enormous amount of b*llshit surrounding shoes. The bottom line is that it`s a hugely lucrative market for someone.