Everything is opinion, but in my expert opinion Bub's system isn't 'sibilant', a system that suppressed sibilance further would be less accurate. Some may well prefer this, especially if they have a preference for poorly recorded music or speech and an intolerance of the consequent spitting. This is a matter of personal taste.
FWIW your old system had a very narrow soundstage, I think this could be generally agreed upon? I guess it is better now, especially if you've removed that cabinet from the rhs of the room.
When I first set the Quads up the other week I had a very narrow soundstage, some rearrangement led to great improvement. I suppose I have to dig out 'Wuthering Heights' as a sibilance check now...
Anyway early September Prescott is on the schedule, probably not the meeting at the end of the month.
Paul