Is the fit wrong on my road bike or is my body too stiff / inflexible? 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.
Honestly, whichever feels most comfortable to you is the one you should go with. Take both of them for as long a demo ride as the shop will let you and don't pay attention to how the fit "looks" in the mirror. Whichever frame you decide on, be sure you get a fitting from a reputable source - ask other cyclists you know to see who has the best reputation in the area.