Well exactly, That's why I think this 'too fast' business is impossible to assess. There's a huge difference between playing for dancers, and how you might like to hear Irish music at home.

"The young dancers there wanted the music so fast he had to play reels for the polka figures of the set."
I don't understand. Polkas are played faster than reels. So shouldn't that be the other way round? If you played reels where you would normally play polkas, you would be playing a lot slower, not faster. And they're a totally different rhythm?!