There are four versions of Update 3 by the looks of it. Apparently which version of Update 3 you get is dependent on your phone model and your carrier. Not sure what the differences between each one of them are, but I would think the same core features should be present in all of them.I have updated my 920 to Lumia Black. The OS version in settings > about shows 8.0.10517.150
Why didn't I get OS version 8.0.10521.155
I am from India BTW.