Microsoft is steadily getting its handle on its device portfolio after the Nokia acquisition. And it is starting at the bottom and gradually working its way up with the likes of the Lumia 430, Lumia 435, Lumia 532 and the Lumia 535. Then we got to Mobile World Congress. Microsoft had taken over the space once inhabited by Nokia and used it to deliver a keynote very early on the first morning of the show. Among the Windows 10 talk was the introduction of the Lumia 640 and the Lumia 640 XL. Both another step up on the ladder from those that came before, and taking it up to around half-dozen smartphones to carry the Microsoft logo. The Lumia 640 has big shoes to fill, coming in as a replacement for the very popular Lumia 630/635. Does it do a good job? That's what we're here to find out.