I am using Opis 4.8 xhigh, in OMP.sh coding agent (full agent built on Pi), with Matt Pocock Skills installed.

I don’t see a particular bump in code quality from Fable 5. In fact, it feels less reliable to me than my current setup. No sure why I am not seeing what everybody else is seeing.

Perhaps OMP/Pi (head and shoulders better than Claude Code) + Matt Pocock Skills already encode all the agentic improvements Fable has?

Opus 4.8 xhigh is my daily driver for everything. I'd say Fable's edge is visible when designing for a complex problem with no obvious, idiomatic solutions. It is good at greenfield designs, and good at pointing out the pros and cons of hard design choices. I now do designs with Fable, and do implementations off those designs with Opus. Pretty happy. For a while I was using Fable for everything, but burned through a lot of real money for not much value, I think for coding its slow and not at all better than Opus.