If you are having trouble reaching the brakes from the hoods, then the reach is too far. Most people have trouble reaching the brakes from the drops, requiring shims or short reach levers. You might also want to look at "short and shallow" bars. The type of curve on the bar made a huge difference for me.
I am 5' 1" (maybe a little less now?) and I had a Trek 5200 (the precursor to the Madone) in a 47 cm. I had no issues with the overall size/fit, but I never really was able to get into the drops comfortably. Since then I bought a unisex frame and built it up with my own components. Getting a the Specialized bar with short and shallow drops, as well as the Ultegra short reach levers made biggest difference in the world. There are several companies that make these typs of bars.
I recently had a custom road bike with more relaxed geometry built for me. I found that they no longer make the Ultegra short reach brakes/levers. I got the new short reach 105s, but the reach is a few mm longer. This, combined with a slightly different bar still gets me comfortably into the drops, but I have to put my hands much further up into the curve to brake there. I am thinking about switching out to the Specialized bars on this bike, as the ones on there, while much more expensive, have bars angled down, in the newer style and I like the traditionally curved ones.
As everyone said, you should not be able to reach the ground with your feet, while on the saddle. I can put a toe down, if my bike is leaning, though.
Last edited by Crankin; 06-03-2012 at 08:10 AM.
2015 Trek Silque SSL
Specialized Oura
2011 Guru Praemio
Specialized Oura
2017 Specialized Ariel Sport