My take on this is simple...if it does not feel right when you ride it, then it is the wrong size for you. As others have said, on the "height" (generally as measured by seat tube length, but sometimes people think about standover height) of the bike, it comes down to two things: (1) not getting "crunched" when you have to stand the bike and (2) being able to adjust the height of the saddle to the pedals...making sure that at the bottom of the "stroke" you have your knees bent a bit.


Also, as I have adjusted to different height bikes, I have found that the dimensions that make it truly comfortable or not is more along the Top Tube length...or distance from saddle to handlebars (in plain language)...you want to look at that dimension on the distance (i.e. Top Tube length) from the saddle to handlebars and on the drop (is the saddle higher than the handlebars or vice versa). It is, generally, more comfortable to have the handlebars a bit higher than the saddle...but...again, ride and decide!


Hope this helps a bit...and welcome to the Bike Forums...you are already getting a ton of good advice here!