I finished the 2nd Lime Green Hat last night. It's the one I made using the Bates Inline hook that I favor.
I put both the green hats together to see if there was a difference in size, and there was. The 2nd hat is in the back. I used the exact same pattern for both hats, but different brands of hooks. I used a size H for both brands, just to be specific. Obviously, the Boye hook I used for the 1st hat is giving me a smaller product. I wonder if I actually crochet a tighter piece because of the type of hook? It's a possibility.