You'd think there would be more info online about Oakley's lenses but I can't find much. I can only offer my anecdotal evidence. I have a pair of Smith goggles with both the blue sensor mirror and gold chrome lens. the blue sensor lens is much better for all around conditions. But, they're not quite dark enough for cloudless bluebird days. That's when I break out the gold chrome lens. The blue is MUCH more useful.
Smiths' Sensor Mirror lens is the best all-around lens I've ever used. You're right that it's a little light for full on bluebird days, but still usable in those conditions.