Good:

DCA, Terminal C only (US Air)
LGA, American Eagle gates (didn't say a word about my sneakers)
JFK, Terminals 7 and 9
LHR Fast Track in Terminal 4 (don't know if the Concorde boarding pass helped)
CZM unless you get pulled aside in the gate screening lineup (this is easy to avoid, however--just count the folks in line)
PHL (didn't say a word about my sneakers, although they made the GF take off her sandals that have a thick heel)

Mixed opinions:

BOI--while they told me I would get SSSS if I didn't take off my sneakers, they were extremely polite, the line moved FAST, and the woman was almost apologetic about saying "Your soles look borderline on the profile." While the process is a pain, I appreciated her courtesy.

Bad:

HNL interisland terminal--bad all the way around. 1.5 hour wait for a 30-minute flight to LIH, then one guy before the WTMD "recommends" that you remove your shoes; the woman on the other side started screaming at my GF to remove her shoes and then, when she did, accused her of "throwing them" at the X-ray operator; meanwhile, I refused to take my sneakers off and was fine, no problems at all, until the woman screener told me to "control" my friend and I told her to "improve your f***ing attitude if you expect any respect from passengers." She then pulled me aside for SSSS, but right then the supervisor walked over and let me go. My guess is that he knew what a ***** she was.

Also bad:

DCA Terminals A and B
IAD