Heh. I hate how they dub the voices in russian localizations. Those so called "professional actors" seem to not pay any attention neither for the context nor to the character, and prefer to read everything in such manner that sounds like they are reading a fairy tale book for kids in kindergarden. Sometimes makes me laugh, but usually bores to hell. Hence I prefer to play english versions of the games when possible.
I remember only one game I played back in 90-ies which actually had better voice-over in russian than in original english. But.... that localization was made by pirates! oh, the irony
On topic. Well, what can I say, except for obvious? If the acting is good I vote for the voice. Otherwise better not. I remember I disabled voice in Laura Bow 2 because some of the actors just pissed me off (sounded too much off-character).
Regarding giving your own voice to characters. That's the same problem as when making a movie based on a novel - if you read a book before you will always be dissapointed a bit because some characters are not like you imagined. On other hand, if your imagination has a right to give character a voice, why game creator's shouldn't? And how can one say that it is their imagination that has higher priority on doing that? I suppose it is rather a matter of getting used to something.
Subtitles is a must have regardless of anything. Even if your game is translated to hungred languages there are still people who prefer to listen to original acting and check text when they do not understand something. I do