IF you plan to fly a cherokee (of any kind) after you get your ppl, it is a wonderful idea to learn from day one in that type of plane.
Having taught in both, I've noticed that people progress faster in the cherokee series for the following reasons:
1. comfort. it can get quite hot during summer flying and the cherokees have optional air conditioning.
2. fewer bangings of head on wing while doing the walk around inspection.
3. Almost never having a fuel shortage problem as it is very easy to visually inspect the fuel on a cherokee without having to climb up on a wing strut like the 152.
4. Checking the stall warner is much nicer on the cherokee.
5. Very little chance of pilot falling out of plane in the cherokee.
6. More payload in cherokee vs 152.
:-)