If you're not racing, Speedplay Light Action ($125) pedals are right at that point. Apparently some of the racers like to have more tension for release, but for most of us they're fantastic and models above that are exponentially more expensive for slightly less weight.
If you are racing, or whatever, some people prefer the Zero's. Apparently they don't unclip quite as easy as the light actions, which the racers and regular riders prefer. I haven't tried them though, so I cannot comment on how big the difference is.
So I would go with the Speedplay Light Action's or the Speedplay Zero's. I would avoid the Speedplay X-Series - I have them, and they're really susceptible to getting clogged up with dirt. Apparently the plastic piece in the other two models keeps dirt from getting into the moving spring (I'm seriously considering the light actions myself right now to replace them).
Speedplays are great pedals because they're dual sided (no looking down or flipping over the pedal at intersections or when getting on and off the bike) and they have good amount of float (let's the back of your foot rotate, usually easier on your knees).
I assumed you're looking for a road pedal due to your mention of the caad9. If you're looking for a mountain bike pedal, that's a whole 'nother topic.