The trick is to keep the 'keen' PPL folk interested enough to complete the PPL in the disappointing C150 in order they can 'discover' the more interesting machines.
These keen folk might not be so quickly disappointed, if they were not being told that they should be! Many of them are probably just delighted to be off the ground at all, and awesomely proud when they do it solo! Why spoil the mood for them?
I know many people who were very keen to learn to fly a floatplane. They would be equally disappointed with an attempt to take off a Chipmunk, as a C152 - from the water!
It's all a matter of your hopes and expectations at the beginning level.....