Theoretically a higher sampling rate is always better. As to whether you can hear it or not, probably not.
DTS vs. Dolby Digital is a lot more than sampling rate though. They are different in a lot of ways. One may be better for Movie X while the other is better for Movie Y (because of the sound engineer on the movie, or the studio that produced the movie, or the company they used to do the audio transfer to Blu-Ray). Better to make sure you can support both. Most people generally prefer DTS when available. But again it may differ from film to film.