Xeney, For what it's worth:
My Rivendell road bike came with a 9cm stem. I had to push my Brooks seat all the way forward on its rails to reach the hoods better, but after a month riding it I still felt too much weight on my hands, and could not ride in the drops at all. The height of the bike was good, as was the crank and seat height and my leg/back position.
Anyway, we switched the 9cm stem for a 5cm stem, and then moved the saddle BACK about a cm so that it was better centered on its rails. End result: handlebars 3 cm closer to me. The immediate difference was incredible- suddenly I could grab the brakes better, ride in the drops, and my weight now felt CENTERED over my whole body and my legs rather than falling forward on my hands. I no longer felt I was trying to hold myself up with my hands. Some people might say that such a short stem will affect my downhill speed and/or my front steering. But hey I just went 36 mph down a hill the other day no problem (i don't need to go faster than that!), I can ride down in the drops effortlessly now, can get my hands all around the brakes now, and I see no problem with my steering...been dodging rocks and gullies on gravel roads for a week now with no squirrels in sight.I am thrilled at riding so comfortable now. So that's my little stem story.