I can only comment on those I've played (or fixed up) - Return to the UNN actually has decent voice acting, not great but quite ok, doesn't make you cringe or anything (well, mostly). Minstrel has no voice acting, for better or worse. Christine's missions, while being an awesome piece of editor work (especially when considering they were all built in the old, non-NewDark editor, which can make mass murderers cry like little girls), indeed do have some voice overs that sometimes make you wish there weren't any.
gameplay-wise, RttUNN is a solid piece of SS2 experience, especially now that the AI ecologies finally work. Christine's missions are really good as well. did not play enough Minstrel to draw conclusions.
Post edited May 27, 2015 by voodoo47