You can actually try them both at 4k and see in person if it actually is a downgrade.
Just looking at the no sound bugs, crashes and issues around changing resolution on the og version of bioshock on some people's systems and o/s indicates some people have some really rosy views of the original pc ports.
https://steamcommunity.com/sharedfiles/filedetails/?id=266981933
http://forums.steampowered.com/forums/showthread.php?t=1133842
Why is this so important for you? People are annoyed some effects are missing, why can't you be okay with that instead of trying to prove them wrong?
Found the graphics ini in the AppData folder. Here's the default "max" settings:
I'm gonna set everything to High/true, and see what happens.
FXAA is on by default? That's nasty. Also no wonder it can't keep 60 on consoles if they didn't bother implementing multi-threading