... snip ... In general, it depends on the time control/who I'm playing: In a game against a master I'll give a takeback, ... snip ...
That I consider a weird idea. I would expect that a master would never ask for a takeback. It would be such an un-professional thing to do, and I believe that for a chess player to become a master (s)he must have to (and would want to and like to) have a professional attitude towards the game.
I offer takebacks all the time, especially after my opponent has taken one of my pieces