Based on my past four days of shaving with the ATX and your review, I ordered an S4 Shark. Waiting rather impatiently for it to show up in the mail.
And while I think the ATX is a great evolution for the head shavers, I'm not as sold on using it on my face.
So I gave it a try yesterday morning and...ummm...no. I'd say you CAN shave your face with the ATX, but it shaves your head much better than your face. Keeping the wheels on the surface as I shave up or down across the jaw line was sketchy at best. Along the jaw line? Forgeddaboutit.
Of course, as with all things Headblade, your mileage may vary. For me, trying to hold the ATX in a way that allows for face shaving, caused me some serious cramping in my hand and carpals. That may be the major problem right there.