OK, so here's the good news. When Apple released iOS 6.11 last week it did fix the problem some European phone users were having with 3G connections. The bad news is that iOS's other network-related problems persist.
To start with the least bad news, iOS 6.1x-powered iPhones and iPads can still give some Microsoft Exchange servers fits. Left unattended, this will cause servers to slow to a crawl -- with Apple devices unable to get mail or update their calendars.
According to Microsoft, the first thing an Apple user should try is to stop using Exchange to update their calenders. If that doesn't work, Microsoft suggests that users work with their Exchange administrator to uninstall and re-install their Exchange account. If that doesn't help, Exchange sysops are encouraged to first throttle iPhone and iPad users' access to Exchange and, as a last resort, to block iOS 6.1 users from Exchange.
As for the continuing trouble with iPhones and iPads with iOS 6.1x and Wi-Fi, things have not gotten any better. The Apple discussion forums still have messages such as "Since I updated my iPhone 4S to iOS 6.1.1 my iPhone isn't able to find any Wi-Fi network at all. I already experienced some troubles with Wi-Fi connection disconnect every few minutes, but now I really got a problem." As before, this problem seems to show up mostly on iPhone 4 models.
Last, and most damaging, the iOS 6.1x lock-screen security snafu is still with us. With this problem, anyone who knows the trick can bypass your iOS 6.1-powered iPhone password and gain complete access and total control of your iPhone.
Apple promises us that they'll fix the lock-screen security screw-up as soon as possible, and the Exchange problem is also high on their "fix it now" list. As for Wi-Fi, who knows? These last problems have been hanging around for months now.