Recently I had a requirement to restore the phone to the factory default and copy only Contacts, Notes and Messages because of the LowMemory issues with my phone. I have faced lot of issues after the iOs 7 upgrade and LowMemory issue was one the one of the major one. It used to crash at least one or twice because of the low memory issue and it used to log in diagnostic report. (Settings->General->About->Diagnostics&Usage->Diagnostics & Usage Data). To fix that issue I restored the phone to the factory default and restored only contact, message and notes.