Minor update: I realized some of the slowness/heaviness was due to animations. Turning them off to match what I had set in 7 made it pretty comparable, so that was nice.
degen The 22 vs 26/27 isn't solely the thing.. it's also the build # as well in the same series.. I know from my own comp different build #s of the same branch will present differently which I find odd and annoying because there's no consistency, but it's reproducible. Instead of using what 10 serves up (which can be quite old in some cases) you could try downloading directly from Intel's site. Their drivers aren't OEM-locked anymore, so you can actually install them on any comp now and see if it is any better. There is also a setting in the W10 new control panel to turn off the OS force-installing drivers for you.. so I'm thinking if you liked that 22 branch driver, if you disable driver force-update in the settings--if you don't, it will re-install what it thinks you should have, you could manually force-install the 22.* branch on top of what's there now in the device manager. Something I've done many times with audio drivers. Might be worth trying. To make your life a little easier while testing, I suggest setting a system restore point before starting.
About Netflix, you don't necessarily have to use the HTML5 player.. you can also use the Silverlight player. On 7 I use waterfox classic 2020.01 still because it's quite comfy for me but I have the useragent adjusted for the netflix site so that it will use the silverlight plugin instead of HTML5, looks better. Pale Moon is an old fork and is too slow for me. To use Silverlight, in any Firefox-type browser about:config settings create a new string "general.useragent.override.netflix.com" and for the string value enter "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:41.0) Gecko/20100101 Firefox/41.0". Leave out the quotes. Of course, also download and install silverlight itself from Microsoft's site.
What version of ditherig are you using? I was testing with 1.11 and I can see a subtle difference when it is active in 10.
Laptop machines are susceptible to manufacturing variances.. display panel, firmware bios, etc. cannot say it is the same machine unless you know for sure the parts and version numbers.