My diagnosis was CIDP before I went there and Mayo dxed me "atypical cidp". they recommended a smaller amount of ivig at more frequent intervals (weekly). I was already on IVIG before I went.
I think if someone has no diagnosis at all, or is having trouble getting their own Dr to do a good work up then Mayo would be more beneficial to them.
For me personally, it didn't make a big difference in my treatment. My own Dr had already done the more important tests (emg/ncv and many labs).
The good thing is if someone wanted to get a lot of testing in one week and be done with it---the bad thing Mayo mainly likes to diagnose,and are not there for the follow up (unless you live there and they are your regular Dr.)
When myself and my doctor called back there several months later to get Dr Dycks opinion on rituxin for me, he refused to give an opinion over the phone. Said I needed to go back out to Mayo, even though my insurance company paid tons of money on testing and he had all my info right there.