Since there are about 10 new threads a week about this system, I thought a generic thread similar to the one the S790 owners have would be a good tool. I'll get around to posting the specs a bit later, but in the mean time, please feel free to post tips, tricks, problems, what have you.
I'll start: I just received the HT-S590 system yesterday. My plasma TV is in the shop at the moment, so I haven't used it with 5.1 sources yet. I have played some songs from my iPod. Many of the surround listening modes sound great. I haven't been able to discern the nuances between them yet.
I fooled around with the placement of the sub some. I found I got a lot more response with the sub in a corner than I did in a 1/3 spot on the wall.