I just picked up a Behringer X-Touch Mini USB Midi controller. That, along with a Lightroom plugin called Midi2LR, lets me control the various slider adjustments in Lightroom with the physical knobs on the controller, rather than using a mouse.
The whole thing is programmable, but I found pre-made Midi2LR presets specific to this midi controller that make the whole thing quite usable out of the box, and it even came with a printable overlay to label the buttons for it.
I had it for about 8 seconds before I decided it needed a little rack to prop it up at 30 degree angle, so I promptly made one out of oak.
I've only played with it for an afternoon. So far, for doing a lot of detailed work on a single photo, I think I'm better off with a keyboard/mouse. For doing basic level adjustments a a whole batch of photos, I can blow through them pretty quickly without taking my hands off the controller, but it's still able to dig in and do more advanced stuff if I need it.
For some reason, the ability to straighten a crooked photo by twisting a knob is very satisfying.
Looks like Grey Man likes your purchase. I am still learning Lighroom so would not know where to even start with something like this. Enjoy your tweaking.