I always thought sliders weren't as optimal for numerical parameters. You not only have to look where the parameter is, but also where the slider is and ensure you are clicking exactly there to make gradual changes from where you are currently. If you click anywhere else on the slider, the value jumps and the change is abrupt. This might be even more important for DCC applications where you have to keep your eyes on the final result more than the controls.
For example Adobe Lightroom uses them everywhere:
The only software I used that had a better alternative was Autodesk Combustion, where it shows where the slider is for ranged parameters, but also allows you to drag anywhere on the control and see the current value. You can also click to type a value if you want:
You can see the control in action here: http://www.youtube.com/watch?&v=MNRNk2vUW8U#t=285
Since I am not very knowledgeable on UX, I am wondering if there are any established thoughts on sliders, regarding their use, and any alternatives to them, etc?