I can't help you with first-hand knowledge, but you can start by looking here. Some of the comparisons (like 「んだ」 instead of 「そうです」) seems to be part of the standard Touhoku-ben fare.
According to the Wikipedia article, there's some good variety for the expression I quoted (「んだ」) in its formal version (which is equivalent to 「そうです」). In Murayama, for instance, it would be 「んだず」,「んだべした」or「んだずにゃー」, while in Shinjou it would be 「んだじゅー」or 「んだにゃー」. I can't find many explanations in that article, but it seems like quite a variety.