I am one of the allegedly rare breed who learned on one type but then switched to the other. Learned on PA28s (160 & 180), but switched to 172 (albeit the RG version) & 182 thereafter. Reason: more space, two doors. Also prefer being able to just step in rather than clambering up on a wing. Still occasionally fly PA-28s, nothing wrong with them, it's really personal preference, nothing else.