Yes, we've all experienced that edge of the seat feeling after an 8+ hour flight at a much lower altitude than the computer flight "planned" higher altitudes that just couldn't be had because of other traffic.
And then the usual lengthy, modified, vectored Camrn or Kennebunk circuits at low altitude into JFK. And mind you, the flight plan burn from TOD to landing is only 2700 Lbs! (The flight plan doesn't put you at 11000 feet 50 miles out in a hold)...It doesn't matter what Dispatch says, or what the fuel release is on the flight plan; going into large congested airports, you had better pack an extra 5000 Lbs, just to keep your seat from getting too hot. :o