I'm a bit surprised not to see the Surface Pro 3 listed here (hell yes, it's a laptop). I'm no fanboy, but I was blown away by the job Microsoft did on this thing - it's truly one of the best displays I've ever seen anywhere - and it's considerably cheaper than most of the competitors you list here, too. It also gets bonus points in my book for its modern and useful 3:2 aspect ratio that doesn't force you to work through the 16:9 HD "mailslot". (Only two of the laptops here are even 16:10, which is still pretty lame.)
As for PWM, I agree stats would be good. PWM is a deal-killer for me - like LED taillights (yuck!), PWM for backlights is horrid and incredibly visually stressing. I'm really not sure it's possible to crank the frequency up enough to keep it from sucking, since the blinking is the fundamental problem, and a great many people are obviously sensitive to it at frequencies that are "supposed to be" way beyond perceptible.