Speaker grills on or off?

I personally don't like to stare into a big black speaker covers, I like seeing the woofers and the beautiful wood veneer. Soundwise I don't hear much difference.

Off, off, always off. I'm told this often leads to a divorce but hey, it leads to better sound.

I have never owned a speaker that I could hear a difference one way or the other. I had Harbeth's and the manufacturer recommended they be left on so I did. The wood on my current speakers (Daedalus) is so darn pretty I sometimes take off the grills just to admire the view but more often than not I leave on the grills and they sound just as wonderful. I think this is another one of those things that audiophiles can get twitchy about for no good reason.

no difference for me, although mfr says they are designed to play with them on. at best, I think with grills on, you keep dust and other particulates from settling on the components and damaging sunlight out too. (I am a little ocd about keeping things nice and clean.)

my Samoyed loves to sleep smack in front of the speakers with my music playing

My son was born during my first few years of more serious interest in audio. He's ten now. I have never taken the chance of using speakers with the grills off.