I was just about to post the same (or similar) "dilemma", though in my case for Win10 (16:9, 1080p). In a way, I've already "solved" it - in 32-bit video mode spectres are practically invisible, and lowering the setting results in a drastic increase in visibility. The examples below (32-bit and 8-bit, respectively) are from Hell Revealed, but it's the same effect in any WAD/map that test. Strangely, when the screen flashes red due to picking up berserk or taking damage in 32-bit mode, they become more visible.
Does anyone know the reason behind this, or if there's another way to tweak the fuzziness? It's more a curiosity than a problem.