Yes, highspeed overnight. You take the last flight out and first flight back in the next morning. Your technically on duty all night long. In JFK they are very senior for Captains and its a mixture of senior/junior for FO's. I think most FO's in JFK do it instead of reserve, while the rest of the lineholders would rather fly a regular line for money/flight time reasons.

I myself LOVE highspeeds. I live in NY, and I'm home all day long to take care of whatever I need to do. I just would prefer to get as much turbine time as I can (just a little CYA for myself). If your a commuter, Comair provides a hotel in JFK during the daytime, so you won't need a crashpad as long as you hold a CD line. It's great for commuting to/from home as well, as you can take an afternoon flight in to JFK and still meet the report time, and on day 3 you can take the first flight out of JFK and be home by noon.