I have a couple of big DMT stones, too that I'm really happy with. They were pricey, but I've abandoned the water stones and even sandpaper because, as the ads claim, good diamond stones cut a lot faster. I like the course combo stone, too, blue and black, if my memory serves me. Great for really removing some steel, if you have to. And darned good for axes, by the way.

In extreme cases and for planer knives (with the handy jig) I like my ancient Makita 300 grit power wetstone. It'll get a chisel suprisingly close ready to use.

Best,
Zach