For my iPad 3 32GB WiFi+3G after update from iOS 6 it had many issues.
In fact I guess all of those described here. And I tried many solutions so here are my results.
Problems after updating to iOS 7:
- slow performance
- 3G often loosing connection
- keyboard delayed reaction
- apps stuck, get frozen or crash
- iPad don't react after unlocking from lock screen or switch between apps
- battery drain
Solution 1 - Erasing and restoring from iCloud backup
Results - iPad is working faster then after update from iOS 6. But it's not so smooth like iOS 6. Keyboard is reacting with little delay and some apps are getting stuck from time to time.
Solution 2 - Erasing iPad, restoring from iCloud backup and resetting all settings
Results - iPad is working much better. Sometimes You can notice not everything is smooth but keyboard react instantly and apps don't get stuck.
Solution 3 - Erasing iPad and don't restore from backup. Instead synchronize files and apps with iTunes
Results - IPad is reacting quite fast. Apps are working well. Keyboard reacting fast and overal performance is very close to iOS 6.
All 3 solutions don't solve battery drain problem.
I hope this helps.