I always ran mine the opposite..I maxed the presence, and turned treble to 0. Adjust up as needed. I fact I do that with every amp. Gives my ears the most bite if you will. Through G12 65s sounded killer.
I've done both, and am currently mixing both. Presence gives more high midrange, while treble is....well, higher frequency.
I've been using an old Marshall 4x12 with G12-65s with mine since I got. That's a magic combination IMO. In fact, I have an extra 4x12 with G12-65s around that I'm in the process of setting up as a stereo rig with the SLO.