As someone who played many, many hours of Dark Souls's PvP, I at least hoped that the PvP in Nioh would be at least serviceable but serviceable it is not.
Here are the issues that I've found so far:
Intense lag, even on a wired connection. People teleporting around is the norm, and this makes stuff like Haze almost useless or random to pull off (and when you do, it likes just not doing the followup).
Stunlocks and cheesey combos are rather rampant, only made worse by the lag. You know what's not fun? People with quick-change scrolls and the ability to insta-cast them, rendering them effectively unkillable until they run out.
Absolutely no level balancing. Like, seriously, why can I match up with someone twice my level? The ranking system doesn't do shit and should not be a replacement for sending me up against people that can 3-shot me while I can wail on them for 12 hits and not get them to half health. While I can understand not wanting to segregate the levels in fear of people not being able to find a match for being too high level (something Dark Souls got around quite handily by the community-made "meta" of level 120-125), at the very least, scale the attack and health of both participants to be equal so that they're doing basically the same damage to each other, relatively (while still accounting slightly for people that focused heavily on levelling health over other things, and still letting people who grinded to high levels have more "options" with skills and ninjutsu/onmyo).
The sad thing is, I feel forced to play the PvP because it's the fastest way to get glory, and I want a darn female skin. Why are they all locked behind a 90k glory paywall? Just let me buy them for 2 bucks or something, this is ridiculous.