The really scary thing is that crass though he may be the unpronounceable one is like the proverbial wise man. He may not always be right but he is never wrong.
When you have the luck and opportunity to fall in with a significant teacher it takes time to reach a level under his eye for you to really begin to be taught.
Switching styles and dojo hoping needs to be weighed against that.
That said - by not exploring and exposing yourself to other arts and styles you run the risk of self/group delusion. Worse - what happens if the first pick is the wrong one. The trick is, like in all things, is to find the balance.
To answer the question - you only start to learn really significant things after some time with the right teacher.
I agree with all of this. My issue was with the assertion that originally started this exchange, that is, that you're no doing "real" aikido unless you're attached to a particular instructor like a young apprentice to an old master in a kung fu movie.