We have tried a few different ones. The good ones are transparent and the bad have a sound to them

For example the super cheap Behringer DCX2496 changes the sound of the mains a bit for the worse, buts the subs are fine.

The high end boxes, mostly designed for live sound, really are transparent and work great.

We listen through DSP all the time, it's only the studio market that resists this idea, live sound, live theater, professional cinema, high end home theater, etc are way down the road on this and it sounds great. When you use a DAW, use plug ins, listen through most active studio monitors, go to a live show, etc you are listening through DSP