Have not tried the 785 version. Bought the "one" a couple of months ago and I am very happy with it. From what I understand, the PC interface is the same. It was totally worth it.
Also, the touch screen works very well, extremely well. It is very responsive. I reduced the brightness a bit and the battery lasted almost 3 weeks on medium usage.
Cannot really make a comparison, but I can offer you my opinion on the "one"... It works very well and both my wife (very important) and I are excited.