First of all, I'd like to say that a lot of the lesser-knowns or even unknowns are great teachers.
They should not be discounted as being lesser-than those with the big names!
Too, I have had classes with a couple of big names and oh what a disaster ...
TBH they did not have what it takes to make a class successful.
Yes there are not so desirable teachers/instructors out there,
but that goes for both the big names, and downwards in skills and abilities.
When signing up for a class, I will suggest, one should know what they are looking for in the class,
and whether they feel their $ will be well spent on it.
It never hurts to research about the leader in advance.
Just as it is important to know how large the class size will be.
Do they meet your personal requirements?