Some measurements to consider, at the top edge of the serration, from heel to tip:
Chaparral SE: 
0.026, 0.027, 0.024, 0.024
Blade stock thickness 0.079/2.0mm
ARK SE: 
0.026. 0.023, 0.023, 0.018
Blade stock thickness 0.079/2.0mm
Z-Cut SE: 
0.019, 0.019, 0.018, 0.018 
Blade stock thickness 0.0495/1.26mm
Considering how much thinner the Z-Cut blade stock is, these are pretty respectable numbers for both other knives. The ARK blade grind is thinner above the serrations because it's a very high hollow grind so maybe a bit more slicy than the Chap but you may not notice it in most uses. 
It micro bevels on the 30 slots just how I like it, and is probably the "smoothest" SE on the Sharpmaker that I've experienced, with none of the typical bumping you get with deeper pointy serrations. 
I really wish all the K390 options were ground like this. 
Of course I had to take a lil peeky peek inside. Interesting that if you pull the pocket clip barrel out, it allows the back spacer to rotate on the one other body screw that holds it and that allows the lock spring to push the spacer. 
 
I love how this knife uses an internal stop pin and I kinda wish all the back locks had it. There's also a lot of lock bar engagement. No idea what the second hole is for? Do the other no lightweight models use a stop pin in a different location or something? 
 
Sharpening on the 30 slots
 
It looks like they buffed the edge on the back side during factory sharpening...
 
...which I think has something to do with the "rolls" that the edge shows from the back side. I can't feel these with my fingers or fingernails but they do reflect light. Very weird. 
 
I was not prepared for the size though, I actually laughed out loud when I saw that it came in the small Spyderco box. The size is really rather impressive, having just a hair less edge length than a Native 5 but being smaller closed, and then being just barely bigger than a Dragonfly when closed but having quite a bit more edge length. I'm not sure if this qualifies as a "little big knife" but I can see it replacing my Dragonfly, and boy is that saying a LOT.
 
 
This might also be my favorite FRN texture design. It feels more grippy to me than the current standard bi-directional texture. I especially like how it has much smaller "flats" around the screw holes and it has a very nice bevel all around the edge that I really wish more FRN molds had, it's weird that this little knife has more handle edge beveling than full size models like the Military 2 and Bodacious. 
 
Overall it's a winner and the serrations definitely pass the test.