I bought an Ativ for my gf, and it's an amazing phone. She really likes it, and before she had iPhones and a crappy Htc wildfire . It costs 200 euros in Germany unlocked, and it's a great deal. It's fast, has a nice screen, expandable memory, replaceable battery. Only con is that lumias have a couple of good exclusive apps (here transit, here lens).
It made me hesitate about keeping my 620, but I really like that I can put in my pocket and barely feel it. My next phone will probably be a 1020 or its successor, when I can afford it.