I ve been experimenting with both since the moment each came out. 4 games, 3 websites and 2 content creation engines later - I think I m ready to share a bit of my experience and opinion.WHAT I VE NOTICED ABOUT FABLE1. Gold in, gold out - meaning I ve had the best results by making all my design decisions before giving Fable the kickoff information and prompt. It s much more comfortable making decisions by itself - decisions it won t tell you about - unless you explicitly tell it what it can and can t decide for itself up front.2. It s a black box - which is an extention of the point above in a way. I ve used the analogy of an agency when I ve described it to people, i.e. it ll take a brief (what Fable itself describes as an order ) and go off and run with it, only coming back once it s done. I once had a Fable conversation work independently for 9 hours buidling out a client self-service portal for me. All I had to do was type Continue once it hit its session limits every 5 hours.3. It s insanely powerful - so if you ve got everything worked out up front by thinking and working through it with an Opus conversation, you can get the most staggering results. It creates its own sub-agents, does its own testing and self-verification, and ships you back a finished product. It blew my mind.BUT I PREFER OPUS 5Why? Because it s not a black box.1. It reports back - it seems to pause at natural phase gates and give an update on what it produced and why. There s a rhythm to it that keeps you the user involved.2. It s just as capable of spinning up sub-agents and doing its own testing and verification.3. It genuinely is a lot cheaper - for example when Fable runs on a task my Claude Max limits burn out in roughly 30 to 45 minutes (Fable is FAST). But then that leaves me twiddling my thumbs. Opus 5 feels more methodical somehow (which might just be because it comes back to the user, resulting in a slower cadence). Or maybe the better way of putting it is that Opus keeps you the developer involved throughout. And it feels like it s more interested in giving you exactly what you want. Fable doesn t do that - it basically just takes the brief and does its own thing.I simply wanted to share my experience as I ve quickly reached the point of familiarity and thought that might be valuable to others who are experimenting with these frontier models.Look forward to your thoughts. Cheers.