I'm using plays.tv & amd gaming evolved, I love it cuz of the highlight record (last few seconds, i use last 20 seconds, but it can I think over 2 Minutes) and ofc it has a manual record session I don't feel any fps drops while recording or anything else, pretty happy with it But but but if you really have money to spend, I would recommend you to buy a Elgato device for recording & live streaming either HD 60 S or HD 60 Pro, you can use it also for other devices like PS, XBOX....
I did use fraps but that could sometimes cause lags GeForce experience works well. Depending on your PC, I find it better to have a HDD (an SSD is even better) dedicated to recording video from Games - makes them easier to find and also doesn’t fill up OS SSD.