I guess the answer depends on what you mean by sturdy. Comparing the Chinook II or the Persian to the BM Osbourne is in a way comparing apples to oranges. Look at the tip shape. The 2 Spydercos have a very finely shaped tip which enables all sors of delicate work. I have used the Persian, for example, to remove insulation from fine-gauge wire. (I have had the Chinook for less time than I have the Persian, so most of my examples will be using the Persian.) I have also used my Persian to punch through and CUT 1/16 inch aluminum sheeting and the point was fine afterwards (the blade needed a little touch up with a sharpmaker. (and please don't yell at me about knife abuse; time was critical, I didn't have anything else at hand.) Anyway, the Persian--and the Chinook II can both take it!!!!! I have not subjected my Chinook to that kind of abuse, but if anything, it seems a bit studier than the Persian. Also, the ergonomics on both are fantastic (especially the Persian). One thing that I love about the Chinook II are the 4 positions that you can attach the clip--making it truly ambidexterous.
The place where you will find a difference in performance (concerning the tip shape) between the Osbourne and the Chinook is in shear strength. If you plan on inseting the tip and prying with it (aaaargh) I doubt it would hold up as well. I hope that I never have to try that one.
I really like the Chinook-- no regrets at all about that purchase.