To honest, I'm kind of disappointed.. it's quite evident in the promo that McAllister may be Red John, I guess it's better than Bertram though. I hope they're both just big Red Herrings and the writers created some eccentric twist the next episode that explains EVERYTHING. From all the clues we received, whether they were just misdirections or it'll make us think 'Oh yeah! It's so obvious.' when watching over previous episodes.
It's really hard to accept McAllister or Bertram seducing a woman like Lorelei Martins, who is, let's be honest, young-ish and could be perceived as hot, when they seem pretty old and really.. how can someone be attracted to them? Unless they have this really seductive side to them, which would be expected I guess since Red John has like hidden identities. Thinking back I can recall McAllister acting like the biggest pervert towards Grace when she was undercover.. or maybe it was all planned or something, but seriously how can McAllister be that charismatic to obtain such loyalty? He seemed so repulsive during that episode haha.
I would honestly love if Red John was Ray Haffner (highly doubtful) or Brett Patridge (100% sure he's dead though, like how can Cho not notice?) or Michael/Bob Kirkland (that's a stretch though). I find them most charming from the list of 7, well not really Patridge but the writer's can easily manipulate him into one that is charismatic enough to get such a follow (can be for the others too I guess, but to me Patridge makes more sense).
As for Bret Stiles and Reede Smith, we can probably deduce that Smith is DEFINITELY not Red John, I would laugh if he was and he would bring humour into the situation. Stiles in my opinion would work but he's just too old so it's weird.
I'm just working from the list of 7, assuming that Red John is on list, but I actually wouldn't mind if he's Walter Mashburn. Would be such a twist and the explanation would be intriguing.
If it's either McAllister or Bertram I feel that the suspense and the excitement I possessed during the show will slowly deteriorate, it's too obvious.
My opinion, feel free to ridicule! :)