If you are looking for comfort and not necessarily speed, you might want to try the Trek Pilot line. They put the rider a little more upright than most road bikes and they come in some nice carbon frame designs. My husband has the 2006 Trek Pilot 5.0 and loves it. He's ridden a number of centuries on it and while he's got old wrist injuries, this bike has kept him comforable even over some rough roads.

Now he's moved on to a steel bike and he loves it even more. The ride and feel is similar between his two bikes, but he loves how the steel feels more indestructable. He bought the carbon Trek figuring that it had enough of the new advances to last him a long time, but ended up falling in love with a 10 year old steel framed bike instead!