It's funny, but in general the younger agents I've encountered have been the friendlier and more-apt to follow the SOP ones. The times I've had no problems at CRW, it's been with 20-ish agents; the times I've been physically blocked from going through the WTMD until I remove my shoes it's been a agents who appear 50+.

Same at many other places in terms of which ones are pleasant, happy, and do the job right... although I can say the worst agents I deal with are the obese 30-ish women and the 50+ men. It sounds like a weird stereotype, but those are the ones who are much more likely to have no sense of humor, force me to remove my shoes even if they are 1/4" thick flip-flops, run my bag through the X-ray multiple times and then ask for a search, etc.