Actually, I as Windows 8.1 users on the notebook'm not necessarily enthusiastic about the operating system, but let me to a lot of reading on the web but convince Windows Phone. Why? First, price / performance - for a little more than 100 dual sim with good facilities! Secondly, Nokia - used to be the best producer ever, never had problems with the "key phones". I also did not want a phone that comes from any Noname ... Third: Easily synchronize with Outlook, etc. Fourth: security - the apps come only from certified Microsoft Store, no antivirus software required. Fifth, Android, nein danke! I've had enough, the whining of my daughter overhanging updates, permanent reset and low battery power your Samsung. Sixth: Apple - unfortunately I have no money shit! Thus, the Lumia came well packed to the appropriate Micro-SIMs I had worried and a MicroSD was ready. Installation was done quickly after something unconventional removing the back cover and off we went. Windows will then set ready, my Microsoft account completed the acquisition of Outlook, all contacts (even Facebook) were immediately available. For me as a smartphone newbie it did not take very long and I felt right at home on the Lumia. The Apps launch quickly (not like on the laptop!) And all responded great. So far I had no dropouts, the updates come in the background and the dual SIM works fine, as before on my Simvalleys. Property me then a few apps installed later, everything went without Aufreger! The battery lasts long enough, though indeed necessary to look for two networks constantly. A super advantage that I now appreciate properly: When a WLAN is nearby, the Nokia connects automatically. For me as a cable Germany customer with the Home Spots and KDG hotspots - saving properly MBs in the internet! Conclusion: It was absolutely the right decision to buy the 630 DS, I can highly recommend it to anyone!