That looks pretty good. Is it strong enough to hold the clamp in while clamping something?
Absolutely. I clamped a piece of 5/4 hard maple, lined it up against the fence, and ripped a perfect 1.5mm strip off the right side of it (the jig is meant to act like a sliding table on the left side of the blade).
@RKA to your point, consider that the clamp is using the whole length of itself, not just a point load. Even on this cheap junk it holds very, very strong. I clamped the maple down as hard as I could and didn't hear any telltale cracking - since stock is being clamped flat to the surface it prevents the clamp from having too much pull upwards. I think the bigger issue is how long the edge will last if it's being constantly abused by sliding clamps.
Since it has worked so well I will probably use it on my upcoming workbench and assembly tables (from Timothy wilmots system workshop) for which I will use hard maple... It should last a long time!
EDIT: Just took a look at the Microjig site - that's really funny as they're basically demoing all the stuff I'm trying to do! Unfortunately their clamps aren't the quick clamp type though, just the screw-downs... having had the quick clamps for a while now I just have no interest in anything else! Hopefully the keyhole bit I try out will make for a simple two-pass process