Fit is really important, but don't automatically reject a bike you think is barely too big. I rode 62cm frames for 20 years because that's the largest many shops stock and they always told me they'd make it work. I was never really comfortable. Rivendell's guide put me on a 65, which I bought reluctantly after they assured me it would fit. Instantly, on the first ride, I was able to go 50 percent farther befor rigor mortis set in. A lot of people ride bikes that are too small, thinking they'll be lighter or stiffer, but for most of us, comfort is more important than a few ounces of weight.