The App Store on iOS7 on my iPad 3 is terrible. It is extremely slow, as in my iPad will sit there with a white screen while the network activity indicator is active in the top left corner of the screen, but the App Store doesn't actually display anything. Sometimes, after a few minutes, it will start to populate some parts of the screen. Other times it will give up and give me some message about not being able to connect to the App Store. Note that network activity and web browsing both work fine otherwise. I'm on a 150mbps down, 10mbps up internet connection with no current issues.
Updating through the App Store is also royally screwed up. Aside from the above issue, which also occurs on the Update screen of the App Store, sometimes the Update screen will just be blank with no network activity indicated when I know for a fact there are updates for my apps (as in if I manually search for one of my apps on the App Store, it will show there is an update available on the particular App's entry in the App Store). Rebooting sometimes helps, but sometimes not. If I can get the Update screen to show anything, I'll try to update a few apps, then suddenly the Update window will remove the listings of all my apps that still have updates available, and only list the last couple of apps that were already updated, presenting an option to run each of those apps. The missing apps to be updated might re-appear in a few minutes, or after a reboot, or might not.
Other issues that bother me include that you can't tell if the shift button on the keyboard is properly activated when your finger is on top of it, since the arrow that lights up when active is completely covered by your finger. Brilliant design there. You could I suppose study the other shift button to see if that has lit up instead, but that needs to be corrected.
Also, everything feels slower, and the battery is draining much faster, even with automatic updating disabled.
After using iOS 7 for a few days, I get the impression that Jobs would never have released it in this state.