well, also since its not specified, whats the equipment/trim level differences, how many miles on the 07, etc. if its an 07 CM limited with low low miles vs a 2010 base work truck double cab then i'd say get the nicer truck. if they are exactly the same and all that, then its down to more room inisde or in the bed....or if u can get used to weird door handles on the back doors or weird proportions with the tiny mid size truck bed...theres drawbacks to each one....You want more interior room? Get the CM. You want a longer bed? Get the DC. It's just that easy!!