I just read something interesting regarding NVIDIA Inspector and Display Settings for DX10 Preview from NickN (the unofficial computer guru and FSX expert) - "In DX10 the application [FSX] will ignore any external AA and filtering commands other than the checkbox and dropdowns in FSX. That is another reason for the perf difference.. there is NO clean and sharp detail AA available in that mode. You are forced to run the low-grade MS hardware set level AA." I suspect this is the reason why I had the best DX10 graphics when I returned my display settings and NI to the default for FSX and turned on AA/AF inside of FSX. The FSX.cfg "tweaks" will still work though. He wrote this post - http://www.simforums.com/forums/nickn-nividia-inspector-sli-settings_topic41980.html - before Steve's DX10 Shader fix but this would not affect the display settings. I recall seeing something like this several years ago but could not find it (from one of the developers of FSX). So we can continue to keep our DX9 settings in the NI and display settings and still run DX10. This will make it easier when switching between DX9 and DX10.
Best regards,
Jim