Just got a new bike with 6700. Is it normal that there is a flap apparently missing on the hood where your thumb rests? I am finding it uncomfortable and also not very logical as water/debris can get into the mechanism rather easily.
Seriously though, there does appear to be a little bit of exposed mechanism up behind the brake lever, near the pivot. I just fit out one of my bikes with these levers and rode them for the first time a few days ago. I remember remarking to myself that it felt a little odd that I could run my fingers over what felt like internal parts. I think it's normal though.
I just dropped the bike for service and asked the tech. He said it was designed that way as the brifter, especially on the left, needs the room when you shift. My other bike with 105 is covered. In doing some searching, it looks like you can change the hoods to something like Hudz and the area is more covered. I may try some of those.