Hello,
I flew 135 cargo out of CLT, and found the controllers there to be excellent, courteous and professional. I would venture that just about every Class B airport has a slowdown of traffic flow due to weather now and again. CLT really gets hammered when there is a USAirways "push", so that might explain some of the snarls.
I'd say the worst place I've personally encountered is LGA, but the controllers there do an excellent job, it's just a pain in the butt to get a word in on ground control thats so frustrating. Potomac approach also has it's moments, especially going into Dulles. Tough job though, and I have a hard enough time "herding" a Beech 1900 around and can't imagine handling all the traffic into a busy airport using a radarscope!]
Regards,
ex-Navy Rotorhead