Not really. Sonnen only is fluent and quick with his prescripted speeches, but once he gets directly confronted in a verbal match he is quite hesitant. Just look at the live confrontations with Bisping.
To hesitate is a sign of intelligency as well. You can't have all the answers for all the questions all the time at the pace he normally throws, specially when you are dealing with another fast speaking, heavy accented, professional trash talker like Bisping and trying to decode all the sarcasm beneath every sentence. No, that example doesn't demerit Sonnen any bit. He got where he is now complementing his fighting skills with his mouth, right?