I'm just curious how long I can expect my slurry stone to last, and if I am wearing my cotis too much or something...

I can for sure tell that the slurry stone is thinner than it was when I got it, and the coti I use most seems to be wearing down as well. I'm getting to where I almost don't want to use it, because it's my favorite one and I don't want it to wear out one day. But... it's my favorite because it cuts so well, so it's dumb to not use it.

I guess I'm just wondering what the life expectancy of a coti is, and how often I should plan on replacing slurry stones?

Because it will probably come up: I know the slurry stone is wearing, because it's developed a ridge in the center. I don't lap it because there's no reason to, but it was flat when I started.