I agree with TightSlot completely. I travel to the USA through Dulles a couple of times a year, and in general terms they have improved enormously over the last 5 years.
The ESTA system should obviate the time-consuming green card stapling [I'm bemused as to why Visa holders still need the white I-94, but that's a slightly different story]. Fingerprints and iris scan only take a couple of moments. And the CBP troops have improved their customer-relationship skills enormously. On the last occasion the guy was charm personified, whereas the woman at LHR on return didn't even bother to grunt or look at me when I said "Good Morning".
They still have trouble managing the queues that feed a dozen or more immigration desks, though
