I'm having the same constraint, 8GB VRAM, and was trying the past months to get a local model running to drive my Home Assistant setup via voice, so many tool calls, little room for errors. I've tried multiple models, different temperature and top p values, different context windows... turns out that a quantized gemma4 is the best pick so far but qwen3.5:9b isn't far off. Surprisingly newer models are not necessarily performing better.