Open GL Knobs, Sliders etc RackAFX too

Has anybody build some nice OpenGL Knobs, sliders, you know Mixing Board Stuff that will work in JUCE? 

I'm also about to use JUCE with RACKAFX but creating my own front End User Interface. Any advice on Performance,

threading to RackAFX Plugins?  Is it going to be fast enough? I'm building for Windows 8 first but then plan on 

porting to most all the Mobile Devices.