If you're going to Asia, a OW award is often a better deal. I recently booked a trip BOS-DUB-LHR-BKK-HKG-LAX-BOS (stopping over in DUB and BKK) in J/C for 130,000 miles. A simple BA/AA award ticket from BOS to BKK would have cost 185,000.
As Spider mentioned, EI usually has great availability in J/C from BOS and JFK. Have made 3 award trips to Ireland in this way and have never had a problem getting the dates I want.