The use of color in both logos is very appealing to the eye. There aren't too many or too few. The problem for the Senators comes in the detail. While I'm glad they removed the team name from the gold circle several years back, we're still a little heavy on the minutia. The Sabres logo features a single small element — the buffalo's red eye — it makes the logo more aesthetically interesting.
A Senator is a person who makes laws. Untrained, he stands no chance against a soldier with a sharpened Sabre.
It's interesting how neither logo really seems to capture the team's nickname. In the Sabres logo, there isn't a sword in sight, as I've mentioned. With the Senators, I see what seems to be a Spartan soldier. Still, the Senators logo is much stronger in portraying its nickname. I also think the color combination is better. I like the Sabres logo back when it was black and red.