Most people I’ve seen in an instance recently has been 2 – 3, and it’s been fairly stable.
Get a bit of hitching sometimes in SC, and the normal “billiards” effect in combat sometimes.
My PC isn’t the flashiest, but runs Elite maxed out @60FPS for the most part (found setting AA at above 4x caused issues in High Intensity, but nowhere else)
Win 7 home
Core 2 Quad Q9400 @ 2.66Ghz
AMD 7870 Gfx (Sapphire OC version)
Boot & ED running from an SSD
100/50 fibre connection (no change to the occasional lag when I was on a 30/10 fibre)
Without evidence, I think that you might be right about the DaMorgs group size; since the game is trying to run P2P you probably have quite a bit of overhead trying to matchmake you to other instances…
Is the group necessary, other than as a roll call?