Well, it took me 8 months but I finally got a Castelli Speedsuit. I ordered a clearance of last years at a good price, but as it turns out they were out of stock. They called my wife (she ordered as a birthday gift for me), told her it was a mistake, but offered the new 2013 version 2.0 for the discounted price. Horray!
I asked on the Castelli website how the 2.0 was different from last year and they said "we have updated the torso fabric to a faster from the 1.0 to 2.0." I got the white to try and keep cool.
I've only done one ride at 20 miles, but I'm in love! What a wonderful feel. The shorts are very comfortable. The pad is a bit bulky in the centerline, but I like how the edges taper more than my Assos Uno so I have less chafing between side of saddle and thigh. The shorts also slide against the saddle better compared to the Assos, which grabbed. The sliding of the shorts on the saddle helps 'things' to stay in the same place throughout the ride.
It is very comfortable! I didn't really notice it being that much cooler, but time will tell when I start to ride in hotter months. I did notice air going around under the arms which felt different from a conventional jersey and was cooler. The fit along the back and shoulders is outstanding. No flapping fabric - it lies down perfect. The pockets are well placed. The very thin edge at the shorts boottom edge feels great and looks neat.
The only negative is I have a hard time getting this thing off. I can't do one arm or shoulder at a time. I have to get both shoulders out but at that point it's a struggle to get the thing pulled down off my back. I'm sure I will figure out a better technique.
The Medium size was perfect for me - 5'-10" and around 145 lbs. I wouldn't consider another size up or down.