It should take you about 30-40 minutes. Legally you can jump in one and fly it as you have an SEP rating. However some time with an Instructor and the POH will prove valuable.
I prefer the Cessna and own one, I also fly a Malibu which is just a big Piper! I also teach in PA28's on a regular basis.
There is very little difference in flying them or handling them as they are certified aircraft and designed to operate in a specific envelope.
Cessna has better ground viz and generally better short field and rough strip handling, the bigger engine Cessna's like mine have better load carrying.
Otherwise easy, just go and do it!