I'd be somewhat surprised if dropping calls has anything to do with Microsoft on a Nokia phone. It's usually call processing or the HW (radio) that is responsible. The OS may play some role, for example, in the form of excessive latency, but it's Nokia's job to make sure the end product works fine. Disclaimer: I did work on some older Motorola phones, and there was a good reason why they had antennas, however small (stubby) they may have been.My girlfriend got bored of iPhone's so went for a change and got a Lumia 920. She hates it, it drops calls all the time, as well it's data connection. She tried complaining but...
EE blames Mircosoft and Nokia.
Microsoft blames Nokia and EE.
Nokia blames EE and Microsoft.
So, unfortunately it's not worked out for her and she can't wait to go back to an iPhone when her contract's up.