I have never really understood the helicopter from Manhattan to JFK except in very limited circumstances. Unless your office is extremely close to the downtown heliport, the time involved to take a car to the heliport (30+ minutes from midtown), a brief wait before your flight (5+ minutes), the short flight (5 minutes), and then a car from the helipad to the terminal at the airport (20 minutes according to the blade site) surely leaves you with very limited savings in time versus just taking a car door-to-door. Unless we are talking about someone who lives or works very close to the helipad, I just don't see this being must more than a status symbol since it probably takes a hour from midtown to the terminal.
Blade has 2 heliports in Manhattan, the E34th location is not that far from midtown and the times I've used it has never taken 30+ mins to get there but if you are leaving midtown at a time where it would take you 30 mins from midtown (which is certainly possible depending on when you leave) then you're also leaving at a time where a car from midtown would take considerably longer to get to JFK. Considering an UberBlack can run $200+ to/from JFK/Midtown and take well over an hour at peak times, Blade Bounce is a awesome service especially if you can get a seat on one of the scheduled flights for $195 its a no-brainer IMO. Now I wouldn't buy it from AA and pay for 5* plus whatever they are charing for Blade but on its own Blade is a great time saver.