I've owned a Wilson Combat Umnumzaan and countless Striders. All of them have been sold or traded. Unfortunately, I regret getting rid of basically every single one. However, I will say that I regret trading/selling my Strider SMFs the most. While the Umnumzaan is a superb knife and one that, without a doubt, can take a serious beating; the SMFs/SnGs offer a few things that I feel the 'Zaan lacks.
Foremost, the size to weight ratio on Striders is awesome, especially with the DGG models. I never had any qualms about EDCing my SMFs, although some people might complain about the space they take up or the non-deep carry clip, I felt perfectly comfortable carrying an SMF daily. I can't quite recall the exact weight specs to compare the 'Zaan and the SMF or SnG but I do recall thinking that the 'Zaan felt quite dense for it's size, which brings me to my next point. All Ti handle construction vs Ti/G10 handle construction. This aspect is certainly a lot of personal preference, but I appreciate the confidence that comes with a G10 scale, especially on a hard use knife. Another thing I really enjoy about the Strider design is the assortment of comfortable grips afforded by the handle design, as well as the blade choil. Reverse grip feels great on a Strider but so does choking up on the blade. I should add though, most of my Strider experience was with the DGG and CC models which are obviously more contoured than the blocky Lego model. Lastly, I enjoy the variety of blade steels offered by Strider since it has given me the opportunity to try out some new steels; namely Z-WEAR, PD-1, CPM154 and I think eventually S110V.
So obviously, I favor the Strider option here. The one aspect that might sway some people is the "pocket feel" of the knives. They certainly feel quite different. The Umnumzaan has a thinner profile and a clip that sits deeper, whereas the SMF/SnG are a bit wider and sit higher in the pocket.
Lastly, I don't own any CRKs or Striders at the moment. But I certainly plan on acquiring some in the future. My current EDC favorites are the Les George VECP (MonkeyEdge V2) and Curtiss F3 (diamond, 4"). Both of which, I highly recommend, possibly more than an SnG, SMF or Umnumzaan. So definitely check those out if you're willing to spend a bit more money.