interesting discussion about model vs harness and the focus of these frontier AI companies.
want to point out a few really interesting things here
1. Claude Code is actually the worst performing harness when using the same model, significantly behind opencode and cursor cli
this is the core reason i've been against the LLM companies focusing their business on locking people into their harness
what they are good at is making great models. they suck at making good harness products, just like how power plants won't make the best dishwashers, and how internet providers won't make the best phones
if anthropic wants to do what's best for their users, they should let people use their subscriptions in whatever harness they choose, not locked into claude code alone
2. fable 5 max is only 1pt above gpt 5.5 xhigh (77 vs 76)
this matches my experience so far - fable 5 does have the big model smell and it's pretty good, but it's not a massive jump forward like their marketing suggested, at least not on building software
this is actually alarming for anthropic because it's very unlikely people will want to pay 2x higher cost for the 1pt difference. my speculation would be that in enterprises people will be restricted to adopt fable & mythos only on some mission critical tasks, not used at scale