Antigravity gives access to Sonnet and Opus 4.6, I would presume most people are using those models rather than Gemini

I don't think you've used it lately. Gemini 2/2.5 were garbage-tier. The flash level models are absolute trash. 3/3.1 pro are state of the art.

I have. 3 is fine, 3.1 is good. But they are terribly slow. Quality is fine but the the only thing they have going for them is flash pricing. Their response performance sucks.