It is hard to tell unless you have a movie soundtrack that has at least DTS-HD and Dolby TrueHD to compare. It is easy to switch to PCM. It really depends on how it is done. I have heard bad DTS-HD and Dolby TrueHD. If you pointed a gun at me to ask me to choose, I would choose DTS-HD, although Batman Dark Knight (which has Dolby TrueHD) sounds very decent.
Before Blue Ray, I always preferred DTS to Dolby Digital. DTS has more presence and dynamic.
Before Blue Ray, I always preferred DTS to Dolby Digital. DTS has more presence and dynamic.