Not for me, it wasn't. About 15:00 my phone briefly dropped off the network entirely and into emergency calls only. It remained like this during my drive home (so many cell site hand-overs) and finally got back up onto it's home network about 18:30.
As of 06:10 on 07/12 and statements to the contrary, I still problems sending text messages and have no data connection in Andover. The usual forced re-registering advice of airplane mode or turning the phone off and on again makes no difference. For me, O2 is still stuffed.