Some years ago I chanced on a blog by an architect, James Black who had a steel Swift fixed gear bike. I found it to be very appealing, but the steel version was more expensive than the Al ones made by Xootr. Even though I had since bought a Brompton, which I enjoy a lot, I bought a Xootr Swift and ride it in rotation with my other bikes. The James Black bike still appeals a lot, as the chromo frame seems more svelte and I still prefer steel to Al. If you aren't familiar with this beauty, check it out at james.architecture. burger.com. The Swift design is one of 3 iconic designs I have always thought to be amazing, the other being the Brompton and the F series Moultons. And, the hype is pretty much true...on smooth pavement it is about as fast as my 700 c bikes although I haven't gotten the gearing above 88 gear inches. The only change I would make would be to increase the wheelbase because I find the Bromptons longer wheelbase to really help its ride.