This is a very valid question and is really the basis of the "Why do my guitar recordings suck?" question.

rbf738 "I guess I'm wondering if there is a substantial difference between what I hear and what the Mic hears or more specifically should I be okay using that tone in a live setting if I'm happy with it and it's just a matter of scaling it back for the microphone?" Yes, key idea here.

We hear things differently than the mic for a large number of reasons. Room acoustics, the human ability to disregard certain sounds to hear others, percieved fidelity versus volume, bone and body cavitation (we actually hear loud sounds through our bodies e.g. bass drum at the parade) and more. The amp is usually not at our ear level. Scaling back volume, distortion and proper tone settings (boost and/or cut as needed to get a great studio sound.)
Remember also that when we reproduce our recorded guitar signal we are usually not using 2 - 12" guitar speakers and 100 watts. If you try to dial in your sound in the headphones or monitors you are already about 50% ahead of most guitarists trying to record themselves. While different mics and mic positions will yield varying results you should be able to get a great sound with a 57 close miced.
Another trick is to not use reverb or delay or any time basaed effects when recording but add them in post production, of course there are exceptions and if you are only recording a single guitar track that is not part of a mix then you can disregard this altogether.

If you could put your ear directly in front of the speaker about two inches away then you would indeed be able to hear exactly what the mic hears and you would be able to adjust from there. Of course that is a skill that can only be used twice...