I have to say gearing is one of the most important things when riding with roadies.

Keep in mind that with a geared bike you can completely change your gear ratio with the flick of a brifter. They can go from 50 GI when climbing to 75-80 GI when on the flats or descending. You have to find a gear that works for you and the ride that you are going on. You may change your cog/chainring often to suit the ride you are going on.