What is the story of 27 inch wheels?
There where already several common sizes near 630 (622 and 635 mm). Was 27" just an effort to create a new fad and make more money? Or is 27" much older?
I usually get annoyed by them. Though I have one bike with 27" and it's fully ok, just a bit difficult to get new tires (at least in the shops around here). The good thing is that frames made for 27" usually have bit more room and of you convert to 622, you can run wider tires.