I think the shoe carnival at EWR depends on the terminal. One of the screeners at the Terminal A United gates last week actually made a point of telling passengers that removal of shoes is not required. Can't speak for Terminal C though.

BWI, DCA, PHX, CLT, and SFO are all shoe carnival in my experience. IAD is mixed---usually okay but a few screeners still enjoy the power trip of "suggesting" (forcing) everyone to remove their shoes.

LAX (T1, T4, T6, and T7) and JFK (T8 and T9) don't even bother suggesting shoe removal and don't seem to care about sole thickness at all; I've worn my running shoes with soles greater than one inch through the WTMD at all of the above LAX terminals since October and was not sent to secondary. Not TSA SOP, but the way things should be done: no metal, no beep, no harassment. ^