Having just returned from Romania, I can certify that all the information I was able to check was accurate -- from restaurant ratings, all the way to warnings about the dogs on the streets of Bucharest! Lots of the usual hotel reviews, tourist destination listings, etc., but also a lot of useful information about possible problem situations and areas unique to Romania.
The best thing I can say about the Rough Guide is this: I was in Romania to adopt a child, and the Romanian agency coordinator (and driver!) keeps a copy with him in his car. If the locals use the book, it must have something going for it.