Like many of us, SU5 was at first a frustratingly mixed experience for me at first. Undoubtedly smoother performance in the air (stutters pretty much eliminated, high frame rate with everything pretty much maxed out), but visually things looked worse (blurry / washed out), very high CPU temps (on the verge of throttling with one spike up to 91 degrees), the occasional CTD, and some weird pixelated artefacts when panning / with some night lights.

Of course many will still have problems, but my SU5 now looks and runs like a dream, and I'm a big convert to the latest blinding bloom / lighting which is actually very realistic to my eyes. Hopefully a few people will find some ideas from how I got here (with many thanks to all who take time to share their problems and solutions!):

• Turned off hyperthreading in bios / Threaded optimization in NVCP: this brought CPU temps down by 10 degrees even with higher object LODs
• Extended LODs to 4.00, set ColorGrading to 0 in UserCFG: this gave trees to the horizon and restored colour variety
• Rolled back Nvidia driver to 466.77: 471.11 was giving me some strange artefacts
• Played around with panel settings: I can't remember changing it (some things slip my mind when in the embrace of a fine Burgundy) but I must have changed my monitor to a preset with really high gamma which exaggerated the washed out effect of the new lighting. Reverting it back to Gaming mode brought all the glorious colours back.
• Spent some of the extra FPS on bumping up render scale to 120 with a smidge (0.10) of sharpening in NVCP (plus 1.00 for ignore film grain as this is a post-process in MSFS which the sharpening can make overbearing).

Maybe more than most of the big updates, this one was a doozy for needing a period of adjustment. But (with obvious and genuine sympathy for those who are still having problems)  I think there is actually a gem of an update at the bottom of all this. 

Good luck everyone!

@scotchegg Thanks for this.  I will try all of it except the hyperthreading.  

My PC doesn't respond well in MSFS to turning off hyperthreading normally, as I have an older CPU with not many cores to start with, plus I have to keep going back to the BIOS to reactivate it for other applications I use, or it cuts their processing speed by nearly half (unless you know a quick way of doing it from windows?).

Much to my chagrin  this hasn't been the best update for me. 
Performance is certainly stellar, but obviously we have the other issues (I am currently struggling with cockpit camera positions), but all we can do is make the most of it until they fix things up - no option if you want to fly.

So sincere thanks for trying to help by posting your findings!

13 minutes ago, bobcat999 said:

My PC doesn't respond well in MSFS to turning off hyperthreading normally, as I have an older CPU with not many cores to start with, plus I have to keep going back to the BIOS to reactivate it for other applications I use, or it cuts their processing speed by nearly half (unless you know a quick way of doing it from windows?).

Bios is the only way I know, and if it weren’t for the temperatures after SU5 I wouldn’t have touched it. 10900Ks run pretty hot anyway, much to my etc. etc.

Just to note, for many of us, the Ultra setting is forcing Medium settings, so people will also need to use a trick from the other thread to fix that issue if they have it. It can be hard to tell in some cases if you have the issue, depending on the size of your display and how keen you are at spotting detail.

I rarely get my [email protected] to go above 50% utilization in MSFS to get to high temperatures. Although panning fast can hit pretty hard the main thread.

3 hours ago, Alpine Scenery said:

Just to note, for many of us, the Ultra setting is forcing Medium settings, so people will also need to use a trick from the other thread to fix that issue if they have it. It can be hard to tell in some cases if you have the issue, depending on the size of your display and how keen you are at spotting detail.

Ultra setting for what?

3 hours ago, Alpine Scenery said:

for many of us, the Ultra setting is forcing Medium settings,  

The poor me has only one Ultra setting (volumetric clouds) and it stays that way.

After doing all that just to get back to where we were, I wish you luck after the next update.