Not sure if this is agreeing or disagreeing with there being astroturfing.
But I'd reckon that the negative sentiments at the top, combined with that there are over eight Gemini 3 posts on the front page recently, is good evidence of manipulation. This actually might be the most posted about model release this year, and if people were that excited we wouldn't have negative sentiment abound.
On most of the front pages, negative sentiments have floated to the top, especially the Antigravity pages.