I couldn't wait to get cyan on my 920. Battery life had taken a major dive and was making me crazy... So I did the NSRT thing. It doesn't roll back to 8.0, just wipes the storage and installs a clean, shiny copy of 8.1.
Word of warning: in addition to doing the backup to OneDrive, hook up via USB to your computer, use file explorer to copy all your music over to the PC, and then use the WinPhone app to copy your playlists over to the PC. They don't get copied with the music and will be lost if you don't.
Now, before you decide to forge ahead... if you're really into games, you want to wait. Game progress is lost in almost every instance. Win 8.1 enables devs to add their game progress data to the backup, but very few have added this feature to their apps. As far as I know (I haven't played every game I have installed), only the games that I also play on facebook (stored on their servers) and the Microsoft games (minesweeper, solitaire, Sudoku) recovered their data. Even my xbox live games like tetris blitz are treating me like a noob.
After updating, I enabled DP again to install update 1 (the live folders addition).
On the flip side, my daughter's 920 is still running 8.1 DP on Black. I call her 920 the "Gameboy." The benefits of cyan are not worth the trade off of destroying her game data.