Hi ronniehuang
I'm learning in a 152 and although I'm quite tall I still manage to fit in (just!). I think I'm at the limit and in hindsight I wish I started in a PA28 which has loads more room than a 152. I'm almost at the end of my PPL training so I've just carried on. When I pass I'm going to swap over to a PA28 simply because of the extra room. I'm not sure about the cessna 172 in terms of being much bigger but I would imagine it won't be far off a PA28.
For me it was just that I had no choice at the time as my school only had 152s. I would suggest having a sit in a PA28 or 172 to compare although they are typically a little bit more expensive per hour. In terms of ergonomics its not too bad but some of the primary instruments are placed seemingly all over the place in a 152. PA28 layout is much better.