Definitely a draw for me as well. I love me some Mick Karn.
If you're going to check out Porcupine Tree for the first time, I recommend you start with either In Absentia
Or Deadwing
Then, go back to the beginning, and then forward. So many different genres represented over the course of their discography, and a HUGE shift when they moved to Gavin on drums.
Their live shit is unbelievable as well. Hope you dig some of it. One of my favorite bands.