I've personally never like Porkers but thought I'd look at a second hand one when I was thinking about buying the Nissan. Looked at a second hand Boxter or Boxter S. I've never like the sound of a Porsche engine. It just sounds tinny and cheap. There's no nice deap grumble at low revs like you've got in the Z and the noise only get worst as the revs get higher with that high rasping noise, sounds like an out of control 2 stroke engine to me.
Didn't like the drive either, compaired to the Z. It just seems plain and normal, nothing exciting at all and nothing that made you wanted to push the car. The Z on the other hand is completely different. The drive is involving and the engine and setup of the car just makes you want to drive it quickly (within the speed limits of course). Sometimes it's a little bit of a handful but being 1 1/2 tones its going to be from time to time, but that's all part of the fun of the Z.
Can't wait for mine to arrive, might even make me get out of bed on time in the morning. Just over a week to go!