I've got the SM and bought the diamond sticks as well as the ultra fine ones. Now I can re-profile and sharpen a knife to razor sharpness using the SM and a strop. The diamond sticks are really a necessity, was not getting anywhere using the brown, coarse ones.
Still, I think I want to try the Wicked Edge. It looks like a cool system and I'm always looking for newer and better ways of sharpening. The one problem I have with the SM is the tip on one side is always a little larger than the other side. As sharp as the knife comes out, I never feel totally confident in my strokes. Being right handed, it feels good when I'm using the right side but not when I am using the left--something about coming across my body make it fell like it's misaligned.
Anyway, from what some have said about their experience with the WE makes me want to try it.
By the way I just bought the Ken Onion Work Sharp and am not impressed at all. I'm practicing on a couple of Delicas and while I can get them sharp they are far from razor sharp. I'm pretty sure that's going up for sale here soon.
But bottom line: Get the diamond sticks for your SM!