Last week Microsoft released Windows 10 Technical Preview for phones on a limited set of device (Lumia 630,635,636,638,730 and 830). The release is a very early look at the next version of Windows on phones and includes a new action center, new photos app, changes to the Start Screen and new keyboard (see my video).
I installed it on a Lumia 630 and have to say I have been impressed with it so far. I think the battery usage is a bit high as I get less battery on my 630 than my sons Lumia 635 running Windows Phone 8.1. Aside from that it has been pretty stable.
So did you install Windows 10 Technical Preview on your phone?