That is why I look at the context of the post, and your post read as "the reviews were mostly negative", which is why I commented. I mean someone doesn't usually say "not great" when talking about something that is mostly positive, it has a negative connotation to it. For example if I heard a restaurant was reviewed as "not great" I wouldn't assume that it got mostly positive reviews, I'd assume it was mostly negative. Or if I was talking to someone and asked how their weekend was and they said "not great", I wouldn't assume it was an average weekend, I'd assume they had a bad weekend and ask them what happened.
So yes if you mean mostly positive with some mixed reviews, then yes we are on the same page.