Yes, I have fireslate countertops and no I'm not particularly happy with them. I was told to apply tung oil initially, which I did, but I find the oil attracts dust even after it's been thoroughly wiped off. Another thing I don't like about it is that anything you put on it that's slightly wet will leave a ring. The area around the sink is a real nuisance as you can never keep it completely dry, so that area has faded to a light gray to white. The only way to remedy it is to apply mineral oil (which I like better than the tung oil), and wipe it down good, but I find it only lasts for a couple of days and needs to be done again. We've had it for countertops for three years now and I can't wait to replace them. If you like high maintenance then this is for you!!