Ego trips are not welcome on my class. Not that I have a lot to say in the matter (not my dojo) but if I notice a particular person who is only there to boost their ego I usually make their lives pretty hard on the mat. Either they get rid of that "extra ego" or I "eventually" get rid of them.
It can be very harmful for the other students in the class and I even know of a incident where a certain student (ego trip) earned the "dislike" of others.
And shall such a practitioner make it through to 4th or above in kyu grades you can rest sure that the superb ego will never leave the guy. Trust me, I know...