Before 5.1 I had issues with sending duplicate texts, and while WiFi is on receiving texts is a pain. They come on 15 minutes late if not more and if someone calls me it'll ring on their end but my phone won't ring and I'll only know they called when I get the voicemail icon. 5.1 seems to have fixed the duplicate text but the late messages and missed calls are still lingering. I don't have any issue with sprint other than these issues and o love my n6 but some things gotta give this has been happening since the n6 release.