Opera Mini - beta is a non-starter.
Nokia Lumia 920, Windows 8.1 Update 8.10.14157.200.
I got my invitation, installed the app from the store, and it won't even start. I tap the icon (either pinned to Start, or in the app drawer), the screen clears, there's a sub-second hopeful pause, and then it crashes. Reinstallation changes nothing.
Too bad, but it's difficult to evaluate something you can't see ... the Emperor's new app?