I’d also suggest SnapXPro 2 if you’re on a Mac.
Yes, if you have streaming rather than progressive download, you do have the chance of missed frames in your recording, but the advantage is that you can record the video to whatever codec you wish on render output and can fix the size of the screen capture so it will work with a default realtime playback setting on FCP / blend with the rest of your project.
The only thing to be really aware of (apart frmo having a fast machine NOT doing anything else) is that before importing anything recorded by SnapX into FCP, open the file in CinemaTools and reconform to the correct frame rate. For some reason FCP reads the QT MOV frame rate incorrectly when fresh from SnapX and you’ll see if coming up as set to 10fps (or similar) rather than whatever you set it in SnapX.
It’s saved my bacon a number of times.
Ben