At 6'2" and 14 1/2 stone, having an instructor who was similarly (and perhaps even a bit better) constructed was a great distraction in a C152. This isn't helpful if you are as lousy at flying as I am.
The lessons where he wasn't available and he was substituted with someone smaller always went more smoothly. With the benefit of hindsight, the extra spent on a 172 would have been worth it.