Draccent,
I am 5 foot 9. I find with the seat fully forward it is just right in a 172.
You need to remember you are used to a 152 where with the seat fully back you are probably comforatable and the seat fully forward you are ready to impale yoruself.
I learnt to fly in a 150/2 and I found it strange in a 172 at first. The other thing to keep in mind is the 172 is a heavier more powerful (don't laugh everyone) aircraft, and that will throw you off for a while and make you feel that you are not properly in control. In fact as you move from type to type you might have similar feelings.