I learned to fly mostly in a 172. The first time I flew a 28 I asked my instructor what the difference was, he said 'The main difference is you have to bend down to take a fuel sample'. One circuit later I was away on my own in it.
Haha, love it. I learned in a DR400, HR200 and a C172 (Majority of hours in the HR200). When I converted onto the PA28, I was told I'd need 2 hours, 1 hour in the circuit, and 1 hour doing upper air work. In the circuit, for the first 45 minutes, I was taught incorrectly, but after the instructor correcting his mistake, 2 touch and gos were done perfectly (I just found it difficult to press the brakes properly due to the weird bit of bodywork across where the brakes should be).
I found the upper air work really helpful, not really for the actual flying/stalling etc, but more for just being taught about the fan controls and cabin heating etc (the little luxuries).
I'm now wanting to convert properly onto the C172, but don't want to pay £360 for two hours that I probably won't really need as I did my first circuits in a 172...