Solo-6 IR keypad works well
Crutchfield Customer Review (What's this?)
We have both Solo-6 IR and Solo-6 MD with LCD display controllers for ZR-6. The Solo-6 MD really shines if you are using a classic iPod to serve your music. The MD LCD display gives you metadata track selection and information from your iPod as well as radio channel info from the integrated ZR-6 radio. Also, admittedly the Solo-6MD units look nicer in the house. However we are almost exclusively streaming music from an internet radio source (Logitech duet) so we really don't use the iPod metadata display features all that much. For that the Solo-6 IR is actually easier, operates with a simple button selection, don't have to go through the LCD menu on the MD. We ended up putting the IR units on the outside of the house and the MD units on the inside for aesthetics. Both units work great and have served us well. I will add that if you have a large music collection on your iPod you may find the MD interface maddeningly tedious and slow since you can only page up or down 5 lines at a time. My wife can work both the MD and the IR units just fine which is the final litmus test in our household.
Pros: Easy to use, good if not using an iPod as your primary music source, good for low-traffic and guest areas of the house
Cons: If you are going to be selecting music from your iPod then spring for the MD (and the MD looks nicer in the house)