Alpha,

Our systems are similiar and after a lot of twiddeling, this is smooth until about 100' on final at KATL and EGKK, the only ones I tested today.

Use this if you haven't: http://www.simforums.com/forums/forum_posts.asp?TID=29041

My FSX graphics: frames locked at 30
                          trilinnear
                          lens flare
                          advanced animation
                 Scenery: LOD Large
                               Complexity 80
                               Mesh res 80
                               tex res 1M
                               water low 1x
                               Scenery complexity 75%(very dense)
                               Autogen 50% (dense)
                               Special effects medium
                               NO airport traffic or AI traffic(I use UTX)
                               1920x1200/32
I have used ASA and FSX weather fairly successfully.
nHancer set up as in the tuning guide, EXACTLY.
Drivers: 182.50
Cockpit only.

I think that at some airports I will always get choppy on final until CS gets rid of the messages between the 767 and FSUIPC which I read will help with smooth flight.

I hope Tim C. will chime in with his settings; he claims to have smooth with a DELL@ 2.6 which I find hard to believe but then I'm not looking at his monitor nor he at mine; one of the problems with reviews and other comments in the various forums. I do believe that Dr. Nick really knows FSX!

Hope this helps.

Jack S.
:)