I get a solid 30fps on my PC with ultra settings at 2048 x 1152 resolution with 2x TXAA. It definitely looks a lot better than the PS4 version. The anti-aliasing in particular makes a big difference in this game since there is a lot of shader aliasing and general crawling/flickering jaggies due to the complex geometry and use of shaders in the game.
I've pored over a lot of screenshots and comparisons and I have never seen an instance of the PS4's textures looking anything but like the "high" PC textures. And that still leaves the ultra textures that are available on PC, if not today then with your next upgrade. Look at the difference between ultra textures on PC and PS4 textures:
PC:
http://www.hardcoregamer.com/wp-content/uploads/2014/05/WDImage7-PC.jpg
PS4:
http://www.hardcoregamer.com/wp-content/uploads/2014/05/WDImage7-PS4.jpg
HBAO+ is a lot more accurate and provides noticeably better-looking shading to a game environment than standard SSAO. It makes a difference to my eyes.
The difference in clarity and detail between 900p and 2048 x 1152 is very significant. People made a big deal about the Xbox One version being 792p, but that is much closer to 900p than 900p is to the resolution I'm running it at. Not to mention that the PC version can be enjoyed at much higher resolutions (like 4k) with a future upgrade.
As for those saying there is no screen tearing in the PS4 version, well you might not notice it but it does happen occasionally. Here is what Digital Foundry said about it:
"When render time runs over budget, an adaptive v-sync kicks in when the game can no longer sustain 30fps, resulting in the manifestation of screen-tear until overall engine load has stabilised. Therein lies the principal difference between the Xbox One and PS4 versions of the game - the Microsoft console runs over budget more often, especially in driving sections, meaning more tearing. Noticeable, but not especially annoying on PS4, the Xbox One version is somewhat more intrusive in this regard"
http://www.eurogamer.net/articles/digitalfoundry-2014-watch-dogs-performance-analysis
You can see an obvious example of tearing at the 5:10 minute mark in this video:
https://www.youtube.com/watch?v=3wpVKDg64Po#t=312
If you are getting screen tearing in the PC version it is because you aren't using vsync, it's as simple as that. I use vsync and get
zero tearing.
I'm not saying the PS4 version is bad, though. It looks really great from what I have seen of it.