Device Lumia 1520
OS version windows phone 8.1 cyan

UI looks bad on 1080p screen.
https://imageshack.com/i/kmi1zvtfj
https://imageshack.com/i/iduEJICij
Downloads stop once the screen goes to idle mode with opera still in foreground and can't resume download(selecting resume won't work as the file stays paused.)
https://imageshack.com/i/p2RQ0g5np
No double tap to zoom when zoom is set to 100%.

That's it for now.

ps: I have been using opera mini 5.1 windows mobile version on my Lumia 710(wp7. Thanks xda!)No major difference in UI.since windows phone version is still early in development Its better if you guys port ios version or tablet version of UI instead of this java/android UI.

Wow! Thank you guys! It's here.
Note only previously registered users are able to download.
http://www.windowsphone.com/s?appid=b3bf000a-e004-4ecb-a8fb-9fc817cdab90. Time for feedback

http://www.operasoftware.com/press/releases/mobile/better-browsing-on-windows-mobile opera mini 5.1 for windows mobile was released September 9th 2010, that was 4 years ago. The timing would be just perfect if they release windows phone version this September 9th.