I purchased 2 of these for a trip to Europe this summer. One for me and one for my lady. After comparing this with the Porter and reading into different euro airlines baggage requirements the Farpoint was the clear winner. I flew with the pack on delta, czech airlines, easy jet, and transavia. No issues at any. One comment I've heard is that the Porter 46 can carry more gear. It's important to remember that some airlines have a weight limit too. The farpoint carries plenty. I was able to pack enough for a 2 week trip through Amsterdam, Prague, Munich and Berlin, without washing much.
I really liked bundling this with the Eagle Creek Pack-It Cube Set. It helped keep my clothes organized and compressed.
Funny story is that multiple times we ran into other backpackers with the same pack. I think they need more colors! That said, it stands true to the quality these bags provide.