I know specialized give a lifetime on the frame and 45% crash discount on frames, I can't speak for cannondale. One of the things which matter to me is service and support and both cannondale and specialized try to earn the customers loyalty.
Yea there are lighter bikes, better specs, better bagains... I believe many of these bargain bikes ride differently, the frame material is a little bit thinner, the frame not so responsive or lively.... Product Development, Quality, Great support and service cost but the question which remains is do you wish to pay for it?
The Allez and CAAD are great quality bikes, they feel so well put together, really solid bikes that will last you, year in year out.... I would happily have an Allez any day of the week, every single one I have ridden has made me smile.
Likewise the CAAD bikes are great they did not jump on the latest fashionable material, they just kept chipping away and evolving and developing great bikes into amazing bikes which are outstanding to ride.
A great frame IMHO is one you don't need to worry about and one which makes you smile