I've used Screenfloow and Camtasia, the latter for several years. If all you need is video screen capture, QT X works great. Camtasia and Screenflow have annotations, call-outs, captions, screen controls (PiP, fades/effectspan/zoom) and much more. Screenflow used to be full-screen only capture, with the ability to crop after the fact. May still be the case. Camtasia allows both adjustable capture and post-capture cropping.