i can't really explain technically what harrisson mixbus is doin' better, when it comes to summing....
to be honest, it's pretty magic and tricky, but it works.....

i was summing for years in logic and never mind......
but once i imported a complete audio track plan into mixbus and took it from there, i could'nt believe my ears...
but to make the difference really obvious and "visible" you need at least some accoustic elements in your track....
the eq's and channelcompressors have fixed ranges and defaults for each channel type......
so it's a different deal on single strips, summing busses and even again on the master channel....
and the all over headrooms and the handling are really like an old desk......this peace of software you really can drive "hot".......so to say......
for under hundered bucks, it's still kind of a miracle what they did there and i'm till waiting for the day, when, after all this rock solid beta thing, they come up with a plug in doin' the same job and it costs a fortune...
and for summing at all....
well, there is a reason for all this summing prozessors, analog AND digital, showing up in the last years....
real summing is not just adding the single levels....
it's also keep them in line with some db law....32bit float internal accuracy leaves lot's of room for interpretation...
but hey, in general we're talking 'bout electronic music here....
and all this music ends up on some ghettoblasters, club pa's or in most cases on some shitty ear plugs....
and all daw's summing processing can cope with that....