Cathay Pacific and Finnair have both had challenges checking me in on my OWE ticket. The issue seems to be linking the correct ticket number and coupon number to the correct flight. They have not given me any grief, other than commenting on the length of my ticket. However it does take about 20 mins to check in as they page through multiple screens, call supervisors, etc...

FYI, my ticket has 4 ticket numbers and 20 segments.

Is it possible to get a paper ticket? I'm not sure I would if I could. I've made a few changes to my ticket and it's been very easy to Skype out to AA's RTW desk. They've made my changes very efficiently. Try changing a paper ticket with an airline service agent who handles 20 airlines and has never seen and RTW ticket before. I'd prefer to spend 20 mins patiently checking in each time to hassling with service agents.

A side comment is that only Finnair has checked me in for another airline, in this case BA. AA could not check me into QF or CX. CX could not check me into BA/AY.