Hi Jiffer,
I've done the Palm Springs 65 and the 55 a few times, and the metric century at Cool Breeze. I can't comment on the Cool Breeze century, but I do know there is more climbing than the metric. The two rides are quite different in several respects. There are a lot more people in the Palm Springs ride, and the SAG stops aren't quite as nice as in the Cool Breeze. Cool Breeze is known for it's fantastic support and SAG stops. You do have to ride along Hwy 101 for a while with cars and trucks going by, but if you stick with other riders it is pretty safe. The downside of the Palm Springs ride is that on the return leg, you are "in town" and have to stop at all the traffic signals. I can't ride the Cool Breeze this year as I am nursing a wrist problem (getting cortizone injections and trying to avoid surgery). I'm sure others on this board can help you out more re: the Cool Breeze century. Good luck!!