When you get to profiling your own rigs, I recommend 3 things:
1) try several different mics. Remember, the SM57 has a unique character. I don't think it works the best for micing amps for profiling, but YMMV. Try a bunch. Think of the Audix I5, Sennheisers, etc.
2) use several mic locations. Of course avoid the center of the cone and the edge of the cone, but really explore that middle section with the mic straight on, angled in a few different ways, and at several distances. The kind of cloth or metal protecting your speakers can filter and change tone, and I find a mic placed less than an inch from the grill isn't the best choice. A few inches back can lessen the impact of the cloth. Of course, you catch more of the cone this way, too, which can be a good thing. If you want to isolate the speaker even more, remove the grill cloth and place the mic close to the speaker. See what you like best.
3) once you find the sweet mic at the sweet spot of the speaker, make A LOT of different profiles of each amp at lots of different settings. You won't love them all, but you'll find, when listening back to the profiles, there's a lot more variety to great tube amps at different settings. The most powerful changes, of course, are by varying the channel volume and the master volume. You know this instinctively by playing your amps, but don't forget it when profiling. As an example, I took 27 profiles of my Friedman JCM800 with the Kitchen Sink mod. They are all different.