Hear hear!
I try to do it if I feel like it (and I do feel like it a lot...) But it depends on the weather, how busy the environment is and whether your captain is comfortable with it.
Especially a Captain you've never flown with will be less tempted to let you switch of FD's. Like today
What's the point of disconnecting if you are following a crosshair?
Still though if you do it, make sure you brief for it as most of the guys flying are quite comfortable with all the automatics in place.
Once decided to switch all off in IMC cloudbase at 300 feet. Captain let me continue as I flew with him before, but gave me a right bollocking after the shutdown checks...
And in hindsight, fair enough!!!
(Still, nice approach though, makes you feel really good)
737 is indeed very nice to fly