Except that you rarely know in advance that it will be that long. Usually it's the long, slow bleed of shorter delays. And this happened only once n my experience but it was a lesson- was waiting in MCI for a flight to EWR connecting to a nonstop to DEL. They announced a multi-hour delay- enough to take the shuttle out to a nearby BBQ place, which people here have recommended in the past. Suddenly they decided to use an incoming flight that was supposed to continue somewhere else and use that aircraft to get us to EWR. The delay was cut in half. Anyone who'd left the premises would be left behind.

I'd vote for the Flagship Lounge but would be darned paranoid about having to go through security again to get to my flight, even using the priority line and would probably allow way too much time.