I lost an elk on a shoulder hit because the screw-in adapter broke at the base of the threaded portion and the broadhead twisted sideways, splitting the first 1/2" of carbon shaft. I only got blood on the first 1/2" of shaft. I don't know, but am guessing that I did not hit the bone squarely, causing the aluminum shank to fracture. It was a bad mistake and it will not happen again. There is no doubt in my mind that the glue-in/glue-on adapters are far stronger....especially in brass. If I ever use a screw-in again, it will have a steel shank.....but, I'd have to test that proposition, because the base of the threads would still be the weakest point. I know, the best solution is to shoot straighter....I plan to do that too!
I agree with Tim about the lighter Grizzlies. I'd not worry too much about matching my field point weight perfectly.....from my experience with CXs,I'd suggest dropping the weight tubes, and going to 125s, or even heavier on the bhd....even to 160 if you have to. Honest to goodness, when you get them tuned right, it doesn't hurt your trajectory nearly as much as you think it will! And the 125 Grizzly is a good head, but the 160 is significantly more substantial.