I installed the Kenwood RCA-700 and it has worked well. I have it attached (with the 2-sided adhesive) behind the wheel pretty much where the fingers of my right hand reach during normal driving.

One initial issue was that the IR emitter wasn't pointed very well at the Empeg/HU. Plus, in its original position, the emitter could get knocked off by my knee when exiting the car.

I solved this problem by molding a little adapter out of epoxy putty that fits the emitter to the back of a cruise control paddle (hard to describe, I should take a picture). Proximity and angle of emitter are much better now, and no problems with my knee!