Surface pens: Are Microsoft's own the best, or are there decent alternatives? It's for a non-artist though so pressure levels is a bit whatever, though I think activation force would still matter for inputting to be enjoyable, and so may texture feel / friction if any of these pens do offer that.
Probably the best option is the MS surface pen 2 with hard nib accessory for best IAF and pressure curve manipilation.
Was looking at various Wacoms the other day out of curiosity. While I'm guessing even the Wacom One beats out my 13HD, I was curious about how Wacom One was compatible with mobile Wacom pens but not the Pro pens used on Cintiq 16 etc. Is there any meaningful difference in tech here, or just a way to separate the range of products?
I would vote latter.
Back in the day, the hardware used in Wacom One and Samsung S-pens (UD series digitizer/pen) were Wacom's professional line, used in products like Cintiq 15X, 17SX and 18SX along with with Art Z series. These provided 500 interpolated lines per inch accuracy (way more than current MPP and AES and probably even Apple Pencil) along with 256 to 512 levels of pressure and tilt on certain firmware versions.
Then around 2003 or so, their sales were stagnant so they started Intuos line using DTK digitizer and pen series that increased the interpolated positional accuracy to 5000 lines per inch and pressure levels to 1024 to make user base upgrade. Problem is, 256levels/500lines were already way beyond what human hands could discern and use. But they had hardware to sell to a limited user base so upgrading was the name of the game.
Now we are up to something stupid like 8000 levels of pressure, but I can tell you my drawings do not look any better than what I use to do with 256 levels of pressure. Diminishing returns hit Wacom hardware a long long time ago for pens.
The discernable performance for pens is definitely somewhere between MPP/AES and UD EMR as far as positional accuracy goes. Apple crossed into UD EMR positional accuracy territory by spending huge money on the physical density of their digitizers. MPP and AES OEMs including MS simply refuses to spend that much on digitizer density due to cost, especially as the screen size increases. That's why biggest Apple goes is 12.9" and you will not see Apple Pencil iMac anytime soon...