I'm not a metallurgist or scientist, I can only speak on personal experiences with standard S30V and 154CM. The S30V does appear to hold an edge "a tad" longer, but it is certainly more difficult to sharpen, AND, I can get a slightly finer edge with 154CM. Maybe that's because it's easier to sharpen, but no matter how I try, I cannot get quite the same razor sharpness out of S30V as 154CM.
So.......based on my experiences and preference for 154CM, my personal tastes would lean toward CPM 154 over CPM S30V, even though the CPM S30V may be a tougher and more durable steel.