So the switch port is very good, looks similar but there are some areas that the PS4 version is better. First of all the framerate is halved. 60 fps on PS4, 30 fps on Switch. Resolution is 1792 by 1008 or 1008p on Switch, while it's 1080p (1920 by 1080) on PS4. There are differences in antialiasing as well. The PS4's implementation seems to be cleaner, and in addition to its 14% increase in pixel count benefits from better image quality. Though it's certainly not a huge difference, but noticeable.
Switch also seemingly has either more motion blur, or a lower quality implementation. As you can see in the opening clips, in motion things are much blurrier on the Switch.
Towards the end of this video you'll see good examples of some other differences between the 2 versions. One is with character model texture detail, and also the way shadows are cast on the characters face. Notice the second to last clip where Blair is talking to the player. His face has more simple shadows and less of them on the Switch. I think this could be a difference in ambient occlusion settings but I'm not entirely sure.
And in the last clip, you can see a big difference in particle effects between the 2 versions. On PS4 you see lots of dust in the room while on Switch you see barely any.
Overall though, this is a great port considering the differences in hardware, and I do hope Outlast II turns out as good as Outlast has on the Switch.
Also, I have done a lot of testing in portable mode on the Switch and the results are similarly positive. Most likely a 720p resolution or close to it, and the same locked 30 fps performance as docked mode.
Thanks for watching. This is my first time using Vegas Pro, so excuse my poor editing skills. Especially when the guy in the wheel chair attacks the player. I should've muted the audio of the Switch version like I did in the other split screen clips but forgot LOL RIP headphone users. Also the hallway clip shortly before it as well