I carry the Topeak, and I like it for a couple of reasons. First, it lets me use it like a floor pump (I remember sitting in the dirt with my previous pump, pumping and pumping and pumping and not getting anywhere, so yeah, floor pump is good), and second, it gives an indication of pressure (not sure that it's accurate, but it's better than nothing). If you can squint at my profile pic, you'll see it mounted on the top tube of my Madone, with two water bottles in place. It's tight, I guess, but it works.