Just uploaded a new attempt at profiling my Mesa. Class A (5 Watt mode), Blues channel set quite low gain, but with the master volume set high. Bass set high and treble midway. Mic used was a KSM 44 slightly above and off axis, a few inches away from the grill.
This rig has quite a few options. Initially it's set up purely as it sounded (which actually got very close after a single half hour non stop refining session without taking a break), with a touch of reverb set to roughly match the sound of the Mesa's own verb.
The sound is initially a more "amp in the room" sound, lots of mids and bass through a studio monitor. Dial up the Presence a little if you want more bite, or use the Studio EQ in the X slot to bring it into a territory that's more versatile for recording with. Various FX abound, green scream for lead etc. I don't recommend diming the gain on this rig unless you're into noise guitar as the majority of the distortion here is power amp distortion (with a touch of preamp distortion), so it becomes distinctly flubby and very noisy at that end. This rig is really that crunch/low to mid gain area (as well as lead when using a pedal), should work nicely with other cabs too, and should give you a nice tone with both single coils and humbuckers.
Hope you enjoy my amp.