Allthough I like having blackscreen on on clan-scrims (to not give away our tactics), it doesn't bother me on publics.
Honestly, after playing a map a few times, you can tell where your killer was simply by the location you were at, the distance of the gunsound, the gun used and the direction of the sound (even if you only hear it in stereo).
Then, with respawntimes being very rarely longer than 7 seconds, spying out enemy plans isn't that much of a problem... and even though the spawntimes are short, the situation will most likely be totally different when you spawn anyway, let alone until you finsish typing it.
I understand that it can be a problem on games without respawns like AA, as you gain an unfair advantage, but with the constant spawning and shifting of the frontlines, it doesn't really gain you much.
So, in short: Ghosting never was, isn't and never will be a problem with RO.