Recently I've found myself getting the evaluation simultaneously from to OpenAI gpt-5, Gemini 2.5 Pro, and Qwen3 VL to give it a kind of "voting system". Purely anecdotal but I do find that Gemini is the most consistent of the three.
I found the opposite. GPT-5 is better at judging along a true gradient of scores, while Gemini loves to pick 100%, 20%, 10%, 5%, or 0%. Like you never get a 87% score.
I am running similar experiment but so far, changing the seed of openai seems to give similar results. Which if that confirms, is concerning to me on how sensitive it could be