I'm using Lumia 620 now and really proud to have it on my hand. Everyone loves the case and when they see the Start Screen, they are so amazed. Well, WP8 is my favorite now. I can say it is stable (for my L620), fluid, fast, and got a lot of features. I love to take photos whenever I like, and Lumia got a lot of camera features. I have checked and re-checked again before I bought it, and Lumia 620 comes to be the best choice for all my needs: 5MP is enough for me + shiny flash, Office on the road, Music and Navigation, games (even there is still a lack of games in Store, but it's fine for me, I don't play game a lot), and the last but not least, the price. L620 is the most affordable WP8 Phone now (in Indonesia, because L520 isn't here yet).
I don't regret to buy a WP8, and it is truly nice. Once you use it, you will hardly leave it - that happens to me now! So if you see complaints around here, you can do some check and rechecks like what I did, and again, WP8 has a lot of choices now, not only Nokia, but also HTC and Samsung. Find the best fit with your needs (and wallet) then try one in Microsoft Store around you, and you will be amazed too.
PS. I never know how the look of Microsoft Store is, because there isn't any in Indonesia. I can only stick to 2 manufacturer: Nokia and HTC, and since I am a big ****** of Nokia, I definitely choose Nokia. =)