We have used Icelandair many times for one way services to/from Europe in conjunction with trans-Atlantic cruises. We have flown from/to Boston Logan, New York JFK, Philadelphia, Baltimore BWI and Washington Dulles; and to/from London Heathrow, London Gatwick, Paris CDG, Amsterdam Schiphol, Copenhagen, and Zurich. Although you do have to connect at Reykjavik Keflavic, we have never missed a flight, baggage has never been lost, the fares have been reasonable, and the onboard services very professional. We have flown B767, B757, and recently B737MAX aircraft with Icelandair.