Well, for the record... Waves don't create braking power, they are for clearing out the muck easier which is what helps braking in mucky terrain. I don't know what you ride, but If you don't constantly ride where it's pretty mucky, then waves shouldn't matter much.
I don't know why slotted and drilled would make a whole lot of difference on a slow bike like the KLR. Not like KLR's are running 100mph all day.
The only thing that makes sense would be SS lines, more rotor surface and larger pads.
I'm always surprised that people are looking for more braking power. I can lock the rear up on demand and I know the front will lock up without trying much. Any more braking power for me and I'll just be sliding in to my stops.
I think you are looking at this in slightly the wrong way Matt. Maximum braking force is not achieved when your wheel locks up, max force is achieved just before wheel lockup. Thus the reason for ABS on vehicles. ABS takes a wheel to the point of brake lockup, releases it, and then reapplies. So if you are locking up your brakes causing the tires to slide, that is detrimental to your bikes stopping potential.
Locking up a wheel isn't hard to do. Not with the EBC or the stock rotor. A larger front rotor helps because it is larger. Think of it as a lever that is attached to the front wheel. Because the EBC is larger in diameter, think of it as a longer lever than the stock rotor. Which lever would it be easier to stop a rotating mass with?
The EBC works better because it has a larger outside circumference to work with. It has a larger mechanical advantage over the stock piece because of this. While you can lock up the tire with either rotor in the right conditions, the EBC will just plain stop you faster without locking the wheel.
And on the drilled and slotted rotor thing, it does add some performance benefits such as cooler running brakes and less brake fade. But as you stated, those won't really help you on a KLR. However, the thing about them that does help a KLR or any other bike is weight reduction over the same piece without them. Any time you can reduce unsprung weight the bike will benefit from improved suspension action.
I hope all this made sense. It was the best way I could come up with to explain it.