Hey their Diabeticdoode,
As for the Factory Head Unit in the newer PT's, its kind of a hard question to answer as everyone hears music differently, so what might sound great to me, might sound way off to you.
With that said, to me, I think the newer Factory Audio set ups are a bit lacking overall, especially in the bass department. Their is little in the way of low end therefore leaving it kinda sorta sounding a bit lacking, and disappointing, but like I say, that is just based on what I hear.
If you choose to go with your purchase (which the PT is really a way cool Ride, and I hope you do get one) you can put in a fairly decent upgraded Audio System that should vastly improve your sound quality pretty easy without breaking too much bank. What I would say would be, should you decide to get a PT, and don't like the sound, then you can look at any one of a number of things to upgrade your system very easy, not very expensive, and in my opinion is probably one of the more worth while investments you can do to your ride, especially if you spend a lot of time driving.
As far as size, the folding seats, and so on make it fairly versatile, and if you don't need the back seat, I have seen many people just remove the rear seat, make a platform, black out or tint the rear windows and use it as a kind of cargo PT, and then if you ever really wanted to get into it, they do make conversion kits to turn the PT into a real Panel Truck as well, though their is some modification, body and paint work to pull all that off, but it can be done as well.
Anyways, that's my 2 cents for what its worth. You go easy, and I'll catch ya later.
Candyman