Screen recording of AIR app on Windows desktop

I have developed an Adobe AIR application for windows desktop that runs at 60fps, full HD (classic display list, not Starling). I would like to record this app being used for promotional purposes, and have tried Camtasia and Action! Recorder (with software encoders), but neither of these achieve the required frame rate.

My PC configuration is:
i7-3930K @ 3.20GHz
32GB RAM
Windows 7 Pro 64-bit
2 x NVidia GT 440 graphics cards
500GB SSD

If I upgrade my Nvidia graphics card to one of the newer models, such as a Geforce GTX 970, I can make use of the NVENC technology that provides hardware video encoding of DirectX or the Windows desktop. Action! Recorder apparently supports the NVENC technology on the Nvidia cards, to provide improved video recording.

Does anyone have any experience of using NVENC to record Adobe AIR desktop applications that use classic display list, rather than Starling, and can I expect to record a decent frame rate?

Anyone?