Have you compared the cost in Avios booked via QR for the same flight? Some redemptions are cheaper through QR than through BA. (You can link BAEC and QR Privilege Club accounts, so that a QRPC redemption is funded with BAEC Avios.) Have you looked at the cash cost of each flight to determine whether you'd be getting decent value from your Avios? Finally, have you considered taking the train (Amtrak) from Manhattan to Boston?