TSA has launched a test program that allows people with Global Entry / NEXUS etc. to an expedited security which allows you to keep shoes / jackets on, laptop / liquids don't need to be taken out, most likely not subject to the "radiation machines". Right now, the test is only with American Airlines & Delta at their hubs in Dallas, Miami, Atlanta, Detroit. I think that it will expand to other airports / airlines in the near future.

Since Platinum AMEX "pays for" Global Entry and this expedited screening is a pretty big benefit, for those who don't have Global Entry yet, it might be worthwhile to apply.