Hmm, 7 hours later and this is where I'm at, finger keeps hovering over abort button, any suggestions?

--- Vis ---
saveprt = true
3159 portalclusters
10425 numportals
5322 numfaces
20850 active portals
0 hint portals
visdatasize:1263608

--- BasePortalVis (20850) ---
0...1...2...3...4...5...6...7...8...9... (244)
8 average number of passages per leaf
218 MB required passage memory

--- CreatePassages (20850) ---
0...1...2...3...4...5...6...7...8...9... (668)

--- PassagePortalFlow (20850) ---
0...1...2...3...4...5...

This is still in the vis stage...

you should probably abort, and check if you can make some small brushes detail brushes and only the big ones that block vision structural.

: [
-Radish stained finger moves closer to big red button-

did you already use detail brushes?

Yeah i already did detail brushes, but not very well it turns out. Did it again, hid everything as i went, pressed invert when there was nothing but micros and deleted a fair bit of rubbish, duh! or even dhu!