Actually, I'm an Apple disciple and I have the Lumia 620 only bought to develop customized Windows Phone Apps. Meanwhile, I find this device really well and am considering at the next contract renewal a Lumia with 6 "display to pick up. Well, back to the Luma 620. In my view, run the installed on it Windows Phone 8 very fast. There is no stuttering, in Windows AppStore there is now a very wide range of apps and that's before installed, free Microsoft Office also quite good to use. What I really like the tiles with a live status. Unlike Android and iOS, where the app icons all around are static on the desktop, the tiles of Windows Phone why I sometime a 6 "device 8 can change their state, and view information. For example, the email client & the Weather app do something like that. I think that's pretty good, want to buy, because there simply is more space for my RSS Reader and various news apps.
In short, who wants to buy this device, makes nothing wrong. It is well made, sturdy and has a good hardware equipment.