I use both steels, and a lot has to do with your blade geometry. I have a tendency to use a 15-17 degree angle on my bevels and find that through heavy use, they both hold an edge well, but the CPM 154 has a tendency to chip a little. Not severe but microchips. I have test knives in both at a deer processing facility. When it comes to grinding the two, I prefer S35VN, but I do all my grinding after heat treatment. Both are really good steels, you can't really go wrong. I'll soon have info on S90 and S125V.