Guardians of the galaxy has some awesome actors in there but i can't have high hopes for a movie where Dave "The Animal" Batista is cast. Hoping they prove me wrong though.
Drax doesn't exactly require mad acting skills. All Batista has to do is look menacing and enraged and cast guttural yells every now and then. Same with Diesel voicing Groot all he has to do is say "I am Groot" and some roars or something. The team revolves around Starlord and Rocket so they will likely have the bulk of the lines in the movie and all of the villains are pretty decent actors.