I am very confused about how to get a correct fit on a road bike. I am female, 5'5", average weight and proportions, and have a 31" inseam. Recently, I decided to buy a Specialized Ruby after trying out my friend's bike and noticing how smoothly it rides. I was told by one LBS that I should ride a size 51cm or 48cm bike but I feel stretched out. They said it's because I'm not used to the position. When I look at myself in a mirror on the bike with my torso making a 45 degree angle from the horizontal I don't feel comfortable. When I ride with that position on the demo bike I feel stretched out and struggling to support my torso at that angle though my arms don't lock.
Another LBS fitter is convinced that I need a much smaller bike and has tried to fit me on the 44cm. My arms do have a slight bend and I am sitting more upright and don't feel stretched out as much.
So, my question is--who is right? I am also thinking about trying out road racing, so getting the correct fit is crucial.