Interesting, so your more serious bike is more efficient at the end of the day. Of course, it's a difficult comparison to make with Big Apple tires, etc., but fun to know anyway. I find that I go a bit slower on the Downtube than the Birdy, and the former has 406 wheels. The Downtube is going to have to be traded in for a smaller bike one day soon, and I'm trying to decide what to go for. Whatever it is has got to fit better in a suitcase but still allow my girlfriend to keep up. I can't afford another Birdy, but there don't seem to be any other small wheeled performance bikes.

Good to hear that there are no wheel problems. Perhaps they've fixed QC issues.