I think mileage varies, based on what you want out of a tablet. For me, 95% of my tablet use is: Web, NetFLix, Hulu, Weatherbug, NFL apps, and about 5 there that are on the MS Store. Really, it's more like Web NetFlix and Hulu being 90%+. There's not a whole lot more i do with tablets. All of that, and a whole lot more, has been on the MS store for a long time.
I will grant you that, for many users, the biggest app store is important. Hey, when I got my 1st iPhone, I was downloading every app in sight. Now, I'm reminded of this when I see the 80 or so apps I've previously downloaded or owned, yet don't even put on my iOS stuff any more.
maybe we're a rare bird, but all I need is: a browser, MS Office Suite, NetFLix, Hulu, Weather app, and a couple others. Anything else is just unnecessary. And Surface does this as well or better than any tablet.
The surface pro is a horrible tablet. It is just a laptop with a touch screen. With no real tablet apps. Not worth it if you want a tablet experience.