First, 
imaffett thank you for your help!
Like others we had to upgrade from 7/8 to 10 due to the OpenSSL alert in GooglePlay and noticed an evident drop in the framerate. In addition, CSS animations became very leggy (on Android chrome 40 framrate is significantly better and CSS animations run smoothly).
One of the thing we had to do is to disable GPU rastarization as otherwise we got incorrect pixel rendering issue on some devices. We opened an issue on that (XWALK-3614) but so far it remains unresolved. Is it possible that GPU rastarization is related to the performance degradation from CW10 (at least for the CSS animations)? Strangely, we didn't see anyone else that complains on this issue, though we've reproduce this issue (on the specified devices) for other applications.
We are really looking forward for a fix for the performance issue introduced in CW10. I believe this issue is critical not only for us...