I probably get a hold about once every two weeks, but almost daily you can count on speed restrictions, vectors for spacing, etc.
I always wonder about the national airspace system when the following occurs: You get a delay with an EDC time on the ground. Then they slow you down enroute, then they take you off the route for spacing, then clear you direct to the "handoff fix" (I don't know the official ATC term for this, I sure some controller could inform us, but it's the fix where center will usually hand you off to the approach facility). But before you get there, they tell you "New York/Boston/Philly/etc. has stopped arrivals, advise ready to copy holding instructions". So you hold for awhile. Approach finally takes you, but before too long you're getting a tour of the Mass, CT, or PA on vectors with approach. Meanwhile, you are watching the fuel tick down ten pounds at a time, wondering exactly what you'd do if the radios go dark. I realize that complete, honest to goodness lost comm situations are rare in part 25 aircraft these days (save for the occasional "oops, I don't know how the headset audio get turned down"), but I always wonder how much mayhem would occur at center and approach if somebody was honestly lost comm going to LaGuardia.