I directed the operational testing of these systems for a DoD agency for deploying them into operational theaters (the safety testing was done elsewhere). We concluded that the Rapidscan was deficient in several respects and we did this with full knowledge and experience with other backscatter X-ray systems that we employed for other purposes. In the end, we selected the L3 system. I have spent many hours in front of the displays of both systems and found the L3 device better at identifying threats and was less intrusive from a body display perspective.
Over at the TSA, it's useful to know that Chertoff has a business relationship with Rapidscan and that the TSA testing (done by someone I know) came to conclusions similar to mine, but were overruled at higher levels in TSA.
Does L-3 offer reduced/eliminated skin cancer risk from uncalibrated back-scatter machines?