The Japanese version of Fallout: New Vegas features lackluster, disappointing dubbing. Considering the number of NPCs and unique voices featured in the English versions of the game, I am constantly irked by running across the voice of the same Japanese actor covering multiple, distinct NPC personalities. Furthermore, nearly all nuances in accent, vocabulary, and delivery of the English dialogue are lost in rather dead-pan Japanese readings. There are some exceptions, of course, and the robot voices are almost always entertaining. As a whole, however, the decision to produce Japanese voice-overs, instead of leaving the English acting intact, significantly detracts from the flavor and variety of the wasteland's myriad characters.
I am tempted to set aside my Japanese edition and import a copy of the 'Asia' release, which, unlike the Japanese version, still features the original English voice acting. For the sake of full disclosure, however, I must admit I am one of those people who always prefers subtitles over dubbing--even when I don't understand a word of the spoken dialogue.