Sound is good, voices though.... I dunno sound for lack of a better word a bit "amateurish" or hollow. From what I've heard so far i prefer the voices (not dialogue) of FO3 more at this point.
Really?! The voices of FO3 were so dull and wooden, like the actors just read from a script with no context as to the situation or whether they were supposed to be angry or sullen, etc. And if I never have to hear the "old man" voice from FO3 in a million years, it will be too soon.
Now, instead of one or two professional actors doing a couple of characters, nearly the entire voice cast are professional actors. Even the children they hired to do the voices for kids (and they got several!) have film and tv credits and prior experience. Now I don't mean to disparage the actors who did voices in FO3, they weren't bad (except for a few that grated, see above), but it seems obvious that they didn't have proper direction or guidance in the recording studio. The fact that this time all the recording was done in California with a huge pool of acting talent and voice directors available from the Hollywood scene shows.
And the ambient sounds! My God, they make the game. It causes the towns to actually sound alive and populated, and adds so much to every world space. And the reverb effect from nearby cliffs or mountains caused by gunshots is wonderful. I just got through fighting a running gun battle in the middle of a sandstorm and the sound of whipping winds and echoing gunfire were great.
I didn't realize what was missing in FO3 until I played NV. FO3 needed some detailed ambient sounds for different environments, or least much better than the ones they had.