I have an IQ-X and Igaro on my audax/touring bike. The IQ-X is great and being able to mount it upside down is very useful (if you like a front rack). I run the two in parallel, so you don't need to switch. However, I've found that you can't run them both together if you need full brightness from the IQ-X while charging something. The dynamo (Shimano DH-T780) just can't give enough power for that. I guess you'd have the same issue with any set up on that front.
Nothing special. I just twisted the front light wires and the Igaro wires... oh wait... I have the prototype, the new ones might have connectors or something?
According to the lovely chap from Igaro they can both be wired straight in at the the dynamo hub, although that might just be for Supernova's. It worked for me for a while but I ended up having problems with my charging unit because it was one of the earlier ones without a stability bank.
I have an IQ-X and Igaro on my audax/touring bike. The IQ-X is great and being able to mount it upside down is very useful (if you like a front rack). I run the two in parallel, so you don't need to switch. However, I've found that you can't run them both together if you need full brightness from the IQ-X while charging something. The dynamo (Shimano DH-T780) just can't give enough power for that. I guess you'd have the same issue with any set up on that front.