I've not had any real issue with any gloves, lobsters, or mittens with my 5600 series 105 levers. When wearing lobsters or mittens, it's easier to hit the paddle with the side of my finger. Neither shifting nor braking on the main lever is an issue.

I'm already having trouble with my newer 5700 series 105 levers. The paddle is smaller and it snuggles right up to the lever without the 4mm gap the 5600s have. When it's wet, I have trouble with both bare and gloved fingers. Can't wait to see what it's like come winter…