Just sorted itself out. It was nowhere near the other two I own in terms of balls and smoothness.
I played the amp exclusively for around 25-30 Hours and all of the caps must have settled in. Now she is consistently a top contender !!!!!!
Still has factory pre's and new SED 6550's since it was shipped with Gold Lion KT-88's from Guitar Center. Also, bias is set to 30, no higher or lower. Higher is too mushy.
Maybe Marshall did not burn the early ones in, because the other two were later April and June builds and banging right out of the box. This one is a February build.
I am thrilled as HELL !!!!!!