I wish there was a way to freeze them too, or that they were absolute instead of relative. As it is now, I always know what percentages I want to end up with, then fiddle around with the sliders until I get that.
Would be easier if I, when wanting 20% military, 30% social, 50% on research, could adjust it one slider at a time, instead of having to juggle all three.
To me, it feels unnecessarily fiddly and cumbersome now. So mostly, I don't change them often because of that.
...
Another suggestion with regards to sliders - in the early part of the game, I tend to go through all my planets every turn to adjust the propagande slider so that I'll (when possible) have the morale I want.
Having, either for each planet, or empire-wide, a slider giving me the ability to instead (optionally) set 'target morale' for my planets, and then the game would auto-adjust propagande to reach that level when possible, would save a LOT on the micro-management in the early part of the game for me. (Which still leaves the micro-management of moving zillions of constructors around in the late part... but that's a different problem.)
/unic