I do feel we made some improvements in this area in V8 though
that has given me hope, and I have bought V8 as I cant stay with V5 forever and V7 lines were awful.
There was also definitely some mention of a fix offered by McNeel involving altering gamma ro 2.2, as I tried it, and it worked, but messed up all the grid line colours, I then adjusted those and got a working environment again, until I went to ghosted mode, and it was ruined. so back to V5 I went.
I will see if I can find that gamma fix someone posted, is there scope in that which McNeel can persue to solve this ?
Gijs De Zwart
it’s still a bit of a workaround though, because it does affect lots of color settings. For example the grid looks really weird with this setting. I hope @stevebaer and @jeff can take note of the fact that gamma 2.2 seems to ‘fix’ display quality to level of V5 on Windows, as it could be a clue that these AA issues have been present ever since there are gamma settings in Rhino.
I dont want to find I have to remain on V5 as the most basic of things, line quality, is lost .
How have other CAD progs fared ? surely us CAD’ers all want lines without twisted ribbon effects. There would be uproar if new GPU’s messed up our beloved CAD progs ?
I am with a latest Nvidia and yet V5 is fine, so whats all this about new cards mess up lines, what is being said is new cards with new rhino is the issue, whilst new cards with old Rhino is fine.
, but messed up all the grid line colours, I then adjusted those and got a working environment again, until I went to ghosted mode, and it was ruined. 
so back to V5 I went.