DS4 Flash Q2/Q4 mixed quant fits on a DGX Spark (a $4000 device which is not particularly unheard of expense for Apple customers), and is indistinguishable for me from Opus for my personal daily use/assistant benchmarks[0].

[0]https://humanparadox.org/local-vs-frontier-benchmarks-for-my... - note here I tested Q8 but have found no difference at lower quant.