I prefer to stick with glucosamine and chondroitin because they have been proven beneficial. Prolonged use of Devil's Claw can lead to ulcers so without studies to show it's beneficial and with that known risk, I stay away from it.
Devil's Claw is a banned substance at competitions, fyi. I would not use it because of that.
My recommendation is to do monthy IV/IM injections of Legend and Adequan. Essentially you are introducing the same things in the feed supplements directly into the bloodstream and cutting out the middle man (stomach lining) which can block out all or most of the molecules we want in the bloodstream to get to the joints.
These injections are much more effective than any feed supplement I have tried and have no negative effects beyond the small risk of injection site infection.
And they are cheaper. They cost me about $50/month per horse while high end feed supplements that have been proven to do something can be up to $85/month. And they are more effective in treating and preventing lameness.