Apple says that "devices updated to iOS beta can not be restored to earlier versions of iOS. "
This is simply not true and I have always been able to downgrade my firmware in the past with a device beta test and of course, the process still works perfectly with iOS 7. In fact, it is extremely easy to downgrade your firmware iOS 7 to iOS 6.1.4 or 6.1.3 and it does not need special techniques.
Here is the very simple step by step process to downgrade iOS 7 to iOS 6.1.3 / 6.1.4:
Step 1: Download the firmware iOS 6.1.3 (or 6.1.4 for the iPhone 5) on your computer from our download page.
Step 2: Connect your iOS device under "iOS 7" to your computer.
Step 3: Open iTunes, select your device and make option + click (shift + click for Windows) the Restore button.
Step 4: Go get your firmware that you downloaded in step 1.
Step 5: Your restore should start normally.
Note: Keep in mind that you can only downgrade the firmware to the latest service available on A5 iOS device, even if you have the SHSH blobs. For older devices like the iPhone 4, you will be able to restore to an older firmware, if you have the right SHSH saved.
