Some men just want to watch the world burn...
Ok, here's my vote and I'll try to explain why to keep it in one post.
I've both P1 and Classic and I prefer P1. Why? Simply put, to me, P1 feels right, Classic feels wrong. I look at P1 and I love it and see P1. I look at Classic and I simply like it and I can't see P1, but it's not accurate to Classic either, seems like it tries to be both and ends up being none.
Classic has always felt "wrong" to me. For one, Classic isn't even P1 and whatever people may say, P1's head is more accurate to P1. Also, in spite of what people generally say around here, my opinion is diferent, Classic is the one that looks more toyish to me because it seems more simple. P1 seems more detailed and intricate to me, and that in my way of viewing it makes it more collectible alike.
Also, I love the articulation of the old bodies and I'm not that big of a fan of the new bodies articulation. I also don't like a lot that the new predators are so heavy, that makes them more prone to fall and get damaged by accident. If it wasn't that I have mine on Detolfs my Shadow Predator would already be ruined after falling after having been in the same position for months... it was with its stand and everything...
But anyway, the majority of people, from what I read around here, definitely prefer Classic over P1, and it seems it's mainly due to 2 things: paint apps and body porpotions. So choose wisely so that you won't feel disapointed. And although my views are diferent, Classic does indeed make a nice P1 anyway, I just prefer the original P1.
Hope this helps, good luck!