updated 03:56 pm EST, Fri February 8, 2013
Suggests 6.1.1 may solve 3G issues
Carrier Vodafone UK is warning iPhone 4S owners against upgrading to iOS 6.1, accounts say. "If you've not already downloaded iOS 6.1 for your iPhone 4s [sic], please hold off for the next version while Apple fixes 3G performance issues. Thanks," reads a text message being sent out to subscribers. Vodafone hasn't gone into any more detail on performance problems.
The next version of iOS is 6.1.1, which entered public beta this week. The focus of the update is the Japanese version of Maps, but Apple may be able to include minor tweaks for other regions. It's unknown if any other carriers are being affected by 3G bugs.