I have heard people say that Crushstation is very loud.  I have the opposite problem.  For me, all of the Crushstation presets are extremely quiet.  I have to boost by 8-12 dB on the per-preset output level to get something approaching unity volume compared to bypass.  Playing with the other parameters doesn't particularly change this.

I am not satisfied with some of the discussion I've seen that chalks this up to different instrument input levels.  That doesn't make any sense—why would the preset be loud for some and quieter for others?

Is there ANY chance that this is some sort of "bad install"?

My expert hypothesis / gut instinct tells me there is no such thing as a "bad install" that would exhibit this type of behavior.  Bad installs usually just don't work at all.  That leaves the largest variable being your setup…. so what is your exact setup?  I'm not suggesting it's to blame yet, we just can't properly diagnose without this sort of information.  Also, have you tried the simplest setup possible and/or different guitars / audio sources?