I am more of a purist. I listen to everything decoded as is. I have played with DSP modes, and sometimes, they can be pleasant. But they also sometimes get things quite wrong. For example, I remember an old Sony decoder I had that when I put on its "mono movie" mode, during the music of the opening credits, I thought it seemed like it was a really interesting and possibly very good effect, putting music all around me. But then the dialog came, and it moved that about as well. That was the last time I used "mono movie" with that processor. On the newer Yamaha receivers I have tried, their "mono movie" mode has been much more subtle, which makes the music in a mono movie less immersive, but does not mess up the dialog as much. But I still do not like what it does with the dialog, and so I don't use that either. With other modes that I have tried, it is a similar sort of result. I may kind of like it for a while, but it seems to invariably mess something up, and then I really don't like it. So for me, I play everything decoded as is.
Of course, people should use whatever modes they like. I like everything as is, others may play their systems differently.