I just picked up a Defy 1 after riding a CAAD 8 for about 10 years. It is a bit more upright, but the difference in the head tube is about 1.5 cm. I gave up absolutely nothing as far as power transfer through the bottom bracket. It is a more compliant bike and a little less repsonsive. I only have a few rides on it, but so far the speed has actually gone up by a few tenths. Calling it a "comfy bike" is placing it in the realm of a hybrid. It is an endurance bike along the lines of the Cannondale Synapse, Specialized Roubaix and Ridley Fenix.

If it fits the rider and their style it is a fine bike.