If you have pets -- especially cats, and kids, you'll want the grills on. A few years ago, I was taking care of my daughter's cats, and one of then poked a hole in the woofer/midrange driver of a very expensive Triad Gold Monitor. The cloth grills were not very protective. So, since I own two cats as well, I had Triad make custom metal grills for all three front speakers. No holes since then.