Thanks a lot for your replies, guys. Unfortunately the trip is likely off now (I must have jinxed it by posting )but I'll keep this info with me for a trip in future.

BTW the US reservations staff were rather vehement that all sectors had to be booked before departure from the US, and that passengers into Scandinavia on UA codeshares were no longer eligible for the airpass, which contradicts website info.

Are the one-way SK tickets mentioned above for $50-$70 as flexible as the airpass?

Thanks again.