Last February, I looked at both of these binoculars (in 7x35 configuration) in Galyans and bought the Nikons. In the store, I thought that the Nikons were the better choice, but if I had it to do over again, I'd probably go with the Pentax or yet another brand altogether.
What I've noticed in the field is that even though the Nikons offer me a 9.3 angle of view, the outer 30% of the image is really soft and curved. It's so soft it's almost to the point of blurry. It's better than not having the field of view available, but it's really noticeable when you're panning from side to side looking across an open expanse of either water or meadow as you scan a tree line.
If I'm standing while I pan with the Nikons, I get a real feeling of vertigo and I know it's due to the curvature of the image. It almost feels like the scene is 'falling in' on you as you turn.
Of course, being Nikons (even if they are Chinese Nikons) the color rendition is excellent and thanks to the aespherical elements the CA is pretty minimal. I like the adjustable eye cups and unlike some other reviews I've read on line, I find the thumb rests to be well made and useable.
It's just the curvature and softness of the outer third of the picture that bugs me.
I don't believe the PCF WP's suffer from this problem as badly. I haven't seen their 7x35's in the field (only in the store where the distances are much shorter), but I used their 10x50's with some folks while we were out looking for Peregrine Falcons that had recently been set free at a local fish and wildlife preserve. During that trial I felt that the Pentax compared very favorably to the Nikon Action Extreme's. It wasn't an apples to apples test in the field since they were different magnifications and objectives and I want to repeat that when I did an apples to apples side by side in the store, I chose the Nikon's because the colors were deeper and the ergonomics were better.
It's just that my real experience with the Nikons looking out over a distance is that they give me vertigo due to an imperfect picture. If you're going to be using them to scan a tree line for a period of hours as you wait for your prey to emerge, if you're like me, you're going to end up with a headache.
And that's not a very good thing to say about a binocular.
They make a great backyard binocular, I've used them for squirrel hunting with pretty good success, and they're the first binocular my eleven year old daughter grabs because the ergonomics are so easy on the user, but they're not a serious hunting or birding binocular. If you really want a porro for hunting, in the same price range I wouldn't hesitate for one second before buying a pair of Bushnell Legends or the Pentax PCF's before I'd buy the Nikon Action Extreme's again.
For birding, in the same price range, I'd be more inclined to look into the Japanese made Olympus Pathfinder EXPS's. They're not quite as wide angle as the Nikons and they're not as water proof as the Pentax, but the detail of the Olympus was almost up to Swift Audubon standards.
Just my two cents...
Take the long way home.