The qc2 is an excellent speedo. It is real light and super blue! However, I fried it because of some stupid wiring mistake late one night.
Its working now....LRP customer service hooked me up with a new one no questions asked.
I am not sure if the reactive frequency software is good for offroad because sometimes it feels like I am getting more power at the wrong times or conversely, less power when I need it.
All in all, great purchase. My only other gripe about it is the blue case is beautiful but it chips and flakes so easily. You need to really baby the thing.
Here is a pic of it, on my xray m18.