Rod,
It won't "fix it all", nor claims to. According to Steve Parsons, if I understand a few basics correctly, there's a lot of airports, sceneries, etc. that were created for FSX that used old and inefficient coding, some going as far back as the FS98 SDK. Apparently there's no way of fixing those kinds of things. He goes into great lengths about how developers could correct these things if so motivated. 99% of it is way over my head in understanding. Read what he has to say about various limitations and coding issues here:
http://stevesfsxanalysis.wordpress.com/2013/09/20/dx10-situation-check/OK - now for what FSX DX10 DOES do for MOST users. Remember there are always those who have problems with ANY - I repeat - ANY software - due to the untold hundreds of thousands of systems, addons, configurations, messed up registries, blah, blah, blah - you name it! And therefore ANY software will have it's naysayers and detractors. (Check out the EZDOK or TrackIR forums for just two examples to see what I mean!) And there are those who refuse to take the leap just because they have ONE aircraft or ONE airport that doesn't render properly under DX10, therefore throwing the baby out with the bathwater and then go about trashing it up and down.
Here's some of what it's done for me. I'm running an I7-950 OC'd @4.2ghz.
Eliminated OOM errors and crashes. (Due to shifting some of the CPU load to the GPU.)
I've been able to push my sliders much farther to the right than I ever could in DX9 without out sure fire, guaranteed OOM's.
This alone, if nothing else, makes DX10 worth it to me! 99% stutter free, resulting in smoothness not possible when I run in DX9.
I've seen over 10 FPS increases - and more - in most places I fly in DX10 vs DX9.
Even when the FPS start to drop in heavy scenery areas (PAKT), flight remains very smooth.
Beautifully rich water and clouds. No comparison to DX9. Hands down.
VC shadows that are not possible in DX9 - although I haven't played with that in the Fixer yet.
The ability to eliminate most of the hit and miss, crappy, FSX.cfg, shotgun approach tweaks.
The ability to set higher wave animation settings with little frame rate hit.
What I've noticed after only about an hour or so of "Fixer" test time late last night.
ORBX lights fixed in the 2 or 3 airports I tried.
Missing night textures fixed. Can't vouch for ALL at this point, but the broken ones I noticed before now work.
Haven't checked out missing AI aircraft textures yet.
As Jeff mentioned, PAJN still has problems with black squares under some of the aircraft on the ground. I'd be willing to bet this will be addressed in the near future.
I can't vouch for the DX10 problems with FTXG at this point. However, I haven't read one single comment - pro or con - about it NOT being fixed. I'll give this a go at sometime in the near future when I install it.
You still have to configure various settings in Nvidia Inspector and a few in FSX.cfg.
Switching between DX10 and DX9 is seamless.
There are some who are having various problems with the Fixer that seem to be related to their unique situations. (Related to my thoughts above.)
I'm sure others will chime in with their impressions as well as the jury deliberates.
Bottom line, (for me): If you don't mind OOM's, stutters, limited slider values, less color vibrancy, wave settings, etc. etc. then by all means stick with DX9 and don't waste your time. Is it a perfect, magic bullet? NO, nor does it claim to be.
