My only real complaint about the current store on w10(not redstone) is the 1~2seconds delay to go back when i press the back button, happens in both my l535 and l640, maybe that's because they're low end devices i don't know. About the new ui, i think it's a step back in a lot of aspects, who thought all that scrolling down to find info is fun ? I kind of miss the more horizontal navigation in the wp8.1 store, i think it kept things more organized, one tab for descriptions, then you swipe to the right and it goes to a tab with the opinions and so on instead of a very long page with everything just thrown together at it, it looks crowded and kind of amateurish. I also don't like the new header(don't know if it's the right term) in the app's page, i prefer the current box with the color of the app and the description inside of it, instead of a photo with a feather effect applied.