I'm not familiar with any accelerometer technology that uses magnetic fields to measure acceleration (I've worked with beam mass and thermal based). The technologies I've worked with would require a substantial and extremely low frequency EM field to cause a disturbance as the technologies have an intrinsic low pass filtering (hence why you can have one in your phone and it remains undisturbed).

As for my original question, don't feel bad Seattle. The price is right and the comments I've seen are only for the App. The head unit is apparently fine. I have no clue, was trying to see if there was further agreement with what I read else where. Any thoughts on the durability of attachment for the sensors? I notice the wahoo ones use zip ties (at least for cadence) instead of the rubber bands.