So, in the drums, I often want the crack on the snare to be plenty loud enough. I also want it to sound like I'm trying to make it loud. When I put tape emulator on the drum bus, I get some compression and limiting that keeps the kick and snare plenty loud, but I also get a little distortion which says to the ear, this is loud! This gets more intense as the drums are played harder and less intense when softer, but the volume doesn't change as much as it does naturally.
It's like making cymbals softer to make a band sound louder. In a bar, the cymbals aren't often Mic'd. So the louder the band, the softer the cymbals in relation. You can do something similar to your recording. If you want your band to sound quiet, reduce the velocity on your midi drum loops but keep the cymbals up in the mix. Or do the reverse for loud.
With the tape emulator, you intentionally create light distortion to advertise the heat of the moment, the passion of the song.
I only use the hiss for amusement, but hiss can be truly amusing in the right settings.