I have a mass 100 (not the Lite) running with my very loud Rivera (Bare) :P Knucklehead. I really like it. It doesn't really change my overall tone much. If anything it warms it up. I could'nt play my Rivera over 1 before. now my sweet spot is 6 on the dirty and 8.5 on the clean. I like that it has a low mid volume and a mid-high volume. The knobs are sensitive and are like having another way to EQ your amp. I keep it on even when I play loud gigs. I keep the low-mid knob of the WEBER on about 4 and the mid-hi knob on about 5 on the loud gigs and about 2 and 3 respectively at home. Never tried any other, but Weber is a good company. I would recommend it, myself. Cheers, Lifted