Lumia 820 O2 UK. I'm a light user (in fact I could live without a mobile phone if I had to). The hardware is great. Love it. No complaints. It's been faultless to date, including updating to Portico a couple of nights ago. I even think my battery life is getting better over time. The OS? I like the clean, ordered look of it. It seems very fast too. It does me fine but then I don't do social networking, music, syncing or clever stuff like that. It doesn't seem to have a plethora of settings to finely customize it, which is slightly disappointing and even I'm rankled by not being able to have user-defined People field names (home, home 2, how innovative). That said, I accept that I've bought into a young OS that has to mature. I believe it has the potential to. Microsoft and market forces will decide if it will. All in all, I like it. Unless it dies into obscurity I'm sticking with it (but those field names MS, please).