Thank you for your comment. I didn't think it was possible to play through the campaign on standard difficulty, while exploring a fair bit of the environment, and make it to the credits in under 10 hours.
To be fair, I don't think I have been paying enough attention to the AI while zipping around the maps shooting everything that moves (while trying to stay alive) on Nightmare difficulty on PC. And to be honest, I'm not sure how an improved AI would impact that style of gameplay. I mean, it would have to be much improved for me to notice it in the midst of all that chaos.
Fair enough, I know that I was very surprised when it ended. I'd read the reports saying '15 hours' too.
I think improved AI would mean there was less onus on the level designers to trap you in a room. Improved AI would theoretically force you to either kill them all because you risked being overwhelmed by superior tactics (instead of superior numbers) or to never ever stop running. I'm definitely not the only person who has found the kill chambers to eventually get on my nerves. Gotta get those demon presence levels down to safe numbers.