[Update]: Horizon Zero Dawn PC Update 1.07 has fixed anisotropic filtering and shader optimization.
While the initial launch of Horizon Zero Dawn on PC was a bit messy, to put it lightly, things have gotten a lot better since then. Many of the crashes have been fixed, the performance has been improved, and perhaps most importantly, the strange mouse sensitivity issues have been taken care of.
The good news only continues with the freshly launched Update 1.06. Not only have two new flavors of crashes been corrected, but the update has also finally fixed the bug that caused Alloy to always walk at a very, very slight angle. While not the biggest problem in the world, this is one of those things that can drive a person absolutely insane once they notice it, so I'm quite delighted to see Aloy walk exactly where you tell her to!
You can also expect to see a couple of minor graphical improvements thanks to the update, as well as even more changes in the future as Guerrilla is constantly updating their "known issues" list. For now, however, you can check out the full patch notes over at the official website.
As for Horizon Zero Dawn itself, I'd say it's now in a pretty good place and well worth a playthrough. So if you've been holding back for all of the various bugs and crashes to get sorted out, now would be a pretty good time to dive in. Or if you're particularly patient, it might also be wise to wait until the upcoming Steam sale as Horizon Zero Dawn is almost guaranteed to be on a discount. Not a massive one given that it only just launched, but even so, any savings are welcome these days.
Have fun, and if you're looking for a few more opinions on the state of the PC port, you should hop on over to Steam.