My buddy who switched to a X5 Legion is having similar issues. Stuck slides with live rounds in the tube when he shoots 147s. It worked a little better with 124 but he is not getting the accuracy he desires. He is telling me the recoil impulse is fantastic but still not getting the desired results that are even close to similar to his Glock 17.
Made me loose some faith in it and I might be back on the Glock train. I am still considering piecing together a OZ9. I love the modular frame but I do not really care for the frills. I would probably buy a frame and transfer some relatively stock Glock 34 components on it.