I use the ProRoute Carradice cape (purchased from Peter White: Very fast, friendly and helpful service too!). I really like the airflow one gets with the cape. Here on the north coast of California, a lot of our weather patterns actually sweep upwards from Hawaii; warmer rain than one would suspect.
In no particular order: The cape has kept me dry on my (former) 4.5 mile commute. I hook the thumb loops over the palms of my hands. I thought about hooking the loops on the handlebar, but if I had to do an emergency dismount, I'd be screwed. The gaiters are too snug, and the zippers are too small; they easily open and the darn things are VERY hard to manipulate into place (to get started) because the parts are too small and one has to bend way over to zip the gaiters behind one's legs. Still, as far as dryness goes, the gaiters do their job. I will seek replacement gaiters in a backpacking store. When clad thusly, the wind is NOT your friend. A passing truck sometimes causes the front of the cape to suddenly flip up. During rain, a puddle forms in the cape where it is suspended between my arms. The cape's flipping up gives me an invigorating splash of cold water on my face. I give the cape a 9.4 on the geek scale, but I happily use it.