I trained on a C172, PA28-140 & PA28-180 and personaly I think that the cherokee is best to learn on because you can spin it, and also the ground rush is not as bad as with a Cessna. Its also easier to check the fuel, flap is not electric (only 3 positions to choose from), and better visability for training (looking out for other aircraft). When you have your PPL a Cessna might be a good idea for looking down at the scenery!
I don't think its a question of which type, I think you should be experienced in both types, because most flying schools in the world mostly operate either PA28's of C172's.
I think if you have a good knowledge of, or flying experience on both types you will feel confident in renting either.
One thing I don't like about a Cessna is that you can't open the engine cowl to see the condition of the engine, electric flaps and that you can poke yourslef in the eye with the pitot tube! Apart from all that I like both types. Go fly both and see which one you feel most comfortable with...
