It feel that it is truly unbelievable how mixed and different experiences people give on this. At my workplace we are now being all forced to the Lumia world. And exactly for instability issues there has actually risen an "aftermarket" for old E and N series phones here.

Don't know if it is somehow related to corporate security level usage, but I can't make more than two or three days at best without having to willfully reboot or get the phone totally frozen. And this is the same for most of us in my work place. If you dare to use the phone for something else than calling and email, you are bound to in trouble. And we are no small or somehow specialized company with it's own computer/security system/servers, but big multinational company that has nothing to do with IT-business. Also our operator that delivers the phones and care is the biggest one in Finland.

My phone has already been (its is less than 5 months old 820) to care because it started to malfunction badly (screen and software. For example using camera would make the screen unreadable). I also tried to take it there earlier because I noticed that I couldn't access our company intranet with computer to which I was using the Lumia as a hotspot. Answer from the Tech guys: "Yes, we can't let Lumia phones in because they are so unstable with their connections and security is not working well enough"

But then again, my dad has the same phone and he totally agrees with you and everyone who says that it is stable and fast and good to use. He likes it because he feels that it is as easy and fast as Nokia 6110 that he used to own so many years ago. And also he tells to you that with this phone he can get to internet

I think that Lumias and their user experience has been designed really really extremely with average Joe Phoneuser in mind