I just finished updating to iOS7 and noticed that it runs poorly compared to iOS6. Safari is very slow and the smoothnes of iOS experience almost dissapered for me. Apps seem to take more time to open, changing screens lags etc.
First, try rebooting your device and see if performance improves. Afterwards, go through EVERY setting there is and make necessary changes according to your needs. If after that, it is still slow/choppy, restore it as new.