1. I go to buy an app, oh, I already own it. I know since it says "Installed". So helpful, now I can go search for it again on my computer. Compare this to the iPhone where it isn't completely idiotic and instead of "installed" says "open" which you can click on.
2. Type "Diasy Disk" into the Mac App Store search. You'll get 5 results that AREN'T "Daisy Disk". That's because Apple couldn't search their way out of a paper bag.
3. Let me send a link to this app to my friend. Of course its buried in an unlabeled drop down since sharing content is a decade ahead of any thinking going on at Apple. Let's not try to get any network affects for these apps, that would be silly.
4. The top 10 is full of apps I already own. Super useful. Really makes me want to open this thing up periodically if I'm feeling spendy. Heaven forbid the tailor that page to at the very least show the top 10 apps I don't own. But we live in a world where selling me toilet paper online is more sophisticated than applications.
4.1. My favorite is that #2 on top free is OS X Mavericks. How about just putting up a banner telling me reasons to upgrade to Mavericks instead of eternally taking up a slot in the top 10 free essentially making it a top 9? Especially when most your customer base is already on Mavericks and thus making that slot the most useless slot ever.
5. Hey what was that app I was looking at yesterday? Welp, since we chose to make it a super-fast amazing native experience, I don't get simple features like browsing history that I'd get from this being in a browser. But hey, at least all these 3d graphics in the Mac App Store are crazy performant right? Now if only I could view two apps at once, you know, like maybe two competitors I'd like to compare, in tabs...
It's funny because they ended up having to mirror the content on the web anyways, so the Mac App Store is now the worse of the two options you get (the other being google -> mac app store pages)