Ok after playing around with it for about 30 mins and messing with settings I can confirm what everyone has been saying. You can have a perfectly playable experience provided you are happy with 30fps, 60fps seems to be a distant dream that's not going to happen, at least in it's current state. For my specs I get framerate jumping between mid 30s to high 40s, at least in the early areas, constant 100% GPU usage. As someone who much prefers a stable 30fps over a constantly fluctuating framerate, I'll echo DF and highly recommend using Nvidias "half refresh rate" driver option in this game, something that can be accessed with NvidiaInspector, and also using 30fps frame limit in Rivatuner statistics, which is part of MSI Afterburner. I'd recommend that over using the 30fps limit in NvidiaInspector as from my experience this tends to increase loading times significantly.
DF recommend this too as the games native 30fps cap has some pretty bad framepacing problems that make the game feel like it's dropping frames all the time when it's not, the combination I mentioned it good for many PC games, and even 60fps games minus the half refresh option, as lots of PC games tend to suffer from frame-pacing problems for whatever reasons.
So anyway, with that combination and everything set to highest settings including "full" for "game quality" that I'm running at 1080p (minus motion blur which made no difference to performance but I don't like it's implementation), the game seems to maintain a perfectly smooth 30fps with perfect frame pacing, at least in the first 30 mins.
My GPU is by no means cutting edge but it appears this is the best any of us can possibly hope for right now.