I was a long-time Viking guy, so I u=was used to having a dry/warm head. I moved to a SANTI suit a few years ago, and one of the things I dreaded was going back to a wet hood... I couldn't have been more wrong.
Most of the time, I wear their 9mm hood... It's comfy and very warm. I also have a 5mm that a wear once in a while.
I have a friend who uses a 10mm Waterproof hood and he is very happy with that as well.
With all these things, the fit is the most critical factor. The thicker hoods are, well, thick, so if their putting pressure on the jaw or something, it's going to be uncomfortable. If you can stand the looks, try one one and wear it around the shop for while to make sure it fits properly..