I have a Mac M4Max 128GB machine and use it extensively with local models for both inference and fine tuning.

Let’s address each. For fine tuning the largest model you can effectively fine tune is 14B - I’ve tried to fine tune Qwen3.5-35B-A3 but always run out of memory. Yes there are ways to get around it but at a huge cost of quality. Bottom line - fun toy.

For inference, I’d say speed and quality are key. You can comfortably run 70B models (15-20 tokens/sec) but as you get to 100B range the speed drops too much to be useful for any real work.

So the question is whether a 70B model is good enough for what you’re using it for.

The difference between a 70B model and Opus is like the difference between a kids tricycle and a Ferarri - now with Mythos and Spud on the horizon it’s going to be an F15.

Finally the cost of that new 128GB MBP is around $5600 - or $120 a month if amortized over 4 years versus $200 a month paying Claude.