I'm with JAE: It's a great shape for me. I don't find a P-Bass more comfortable than other basses, it's just what everybody is used to. As a pick player, the Explorer let's me rest my arm, yet at the same time I can anchor or move it with my arm - I like that manoeuvrability -, all very convenient and never getting in the way of my playing. But then I have been playing TBürdse and Explorers for so long, it comes natural to me.
I guess I'm weird, I also think that a Flying V is the most comfortable bass sitting down if you use the "Spanish position". Try doing that with a P and playing for an hour in the high register. I find my right elbow has to stick out too much if I play a P in a standard seated position for long.
No one will ever convert me to "F-type basses", Ilan, I'm a lost cause. That said, I find the J shape much preferable to the P and more comfortable too. The P is a slab of wood just hanging there for me.