Whatever age the airframes - 2 hours in an ATR is long. I had the dubious pleasure of flying from MIA to PTP on one of those. American Eagle operated a flotilla of them out of San Juan to all the Caribbean Islands. It was interminable. The distance is about the same. That said - it is far more convenient than a jaunt around the M25/M23. Since the M25 is 100% unreliable, I'd rather arrive at LGW shaken if not stirred than put up with a bus or whatever.