I am thinking of upgrading from passive optical slave triggers to a pair of radio units. I have Pair Quantum Q flash units - is there any reason to not consider going into a pair of Quantum Free X Wire. Reliablility, ease of use, false triggers, or other concerns from current users would be appreciated before committing cash. Also, there is a current $50 rebate on FW9T & FW8R - but not on FW10 - that I would factor into the decision.