I have the 501s, great video quality and I've not found shake to be a major problem. Battery life is pretty good. RTH works well as does follow me mode. I avoided the Pro version and added the range extender antennae for a tenner, I now have a 1/4 mile or more range.
In the controller I removed a small plastic bar and made room to fit a small LiPo battery which has so far lasted around 15 flights on it's first charge.
This YouTube vid is of my 1st ever drone flight, any jerkiness is down to my poor and erratic use of the control joystikcs and not knowing how to combine stick movements to produce smoother turns.
I've yet to manage out on the boat with it as winds have been too strong!https://youtu.be/zXEbLhEyZ_E