Sorry but you're wrong. Calculating distance from steps is absolutely inaccurate. Sure, if you just walk and you do it always at the same speed, you will have a very small variation on your stride length and the distance would be more or less precise. But if you take running seriously (interval trainings, fartlek, changes of pace...) you NEED GPS to calculate your running pace and your distance, because stride length changes A LOT while doing serious training.
Don't justify it. No GPS is a total fail for runners. Right now it's just an iPhone accessory that tracks your steps (just like the 5s, 6 and 6plus). For sedentary, overweight people that's ok, but not for runners.
I'm just talking about its (poor) fitness features. I know that a lot of people just want a watch to make calls, receive notifications, etc. and for that the

Watch seems to be the best option.
Personally, i'll wait 2-3gens for the GPS.