Hidden tracks, as opposed to Bonus tracks can often compliment an album's flow quite acceptably, as Travis have done several times.
Maybe the fact that Europe and Oz and Jap get bonus tracks is to compensate for the ridiculous amount of intimate gigs played throughout North America. Didn't Boston have about 6 shows for the Vertigo tour, while we in Melbourne only had 2 stadium gigs, when 6 or 7 Rod Laver gigs would've been rather nice for us, if we were treated the same way as North American fans, and treated as fans of the band, as opposed to just masses of people who like a big-time event.
Actually, I know this compensatory theory isn't real, I just feel like having a whinge.