I still use nodewebkit 10.5. I usually preview to that.
Few things (and instructions):
1. capturing video at 60fps is demanding. I have a very good processor (i5 3570k), and I still had to tweak my settings to get smooth recording. Resolution makes a big difference; if you don't have a dedicated GPU, you won't be capping smooth gameplay at 1080p60.
2. There is an option under video that says 'disable aero'. I'd recommend it. Also, I run OBS as 'administrator'. TBH, I forget exactly why, but go ahead and do that too. Otherwise, stick with defaults.
2a. If you want, you can go under encoding and up your bitrate to 10000 or even 20000, but you might need to back it down later if capping is dropping frames.
4. First bring up C2. Preview your game with node webkit. Then go to OBS.
5. First you add a scene. Call it whatever; 'game rec'.
6. Then you add a source. Don't chose 'Game Capture', instead chose 'Window Capture'.
7. Configure according to the window below:
8. Once added, press 'start recording' on the main window, and go play your game. When you are done, stop the recording, open 'file', and then 'open recordings folder'.
9. Name of the file will be the date and time of recording (24 clock). eg. "2015-05-27-1556-51.mp4".
Post back if you have any issues.