Hi Dave,
Describing the difference between PP & SE is very difficult to put into words.
I have heard plenty of both, from simple to some amaizingly complex, including one off Hi-fi diy's to comercial.
The answer is, you need to listen to both and decide for yourself. There are certainly merits of both types and although I personaly prefer SE I wouldn't knock PP at all.
Speakers have a large part to play in the deciding factor. I often wonder if it's the speaker that makes the decision for you....
Ask around and see if you can't get invited for some friendly demonstations, It's prob the best way. Not much help to you now I know, sorry.
Darren