I actually read Dr. Thompson's entire textbook on TOS. (I highly recommend it, but you have to buy it from him because it is out of print.)
Then, I actually flew to Denver from CA, just to see him (on my own dime), and two years into my symptoms.
I was very disappointed because he seemed to be leading the questions and providing the replies, and would not allow me to elaborate on MY own symptoms. When I left, he said he suspected I actually had pec minor syndrome ... which I did not! I followed his advice, but Botox in the pecs actually made my shoulder problems worse, whereas botox in my upper traps & overworked rhomboids had previously helped reduce the pain.
When I left Denver, airfare, hotel, and over $400 later, I felt like he was trying to have data to support his new theories, and diagnosed me with pec minor syndrome instead of TOS to add a name to a list.... but it wasn't me!

The disturbing thing is, I'm actually a clinician and I know the exams, the results, the lingo, and most of all, what I'm feeling. 80% of most diagnoses can come from taking a good history and exam! Now I feel that a family practice doc or neurologist who says they've never seen TOS is mistaken. They simply don't know how to diagnose it!
(On another note, I bought 5 copies of his book, and dedicated some to the several doctors who had missed my diagnosis!)
I don't want anyone to go what I went through just because a doctor isn't well informed about a condition. This action actually saved a colleague of mine from ending up like me, all because we had the same doctor and he'd had me first so he recognized it in her!

Sorry, I'm rambling...!