Day 2 of using Fable as my main model in Amp.
Some impressions.
It's smart, yes. The codebase for the new Amp contains a lot of intricate dist-sys business logic: this resource has this lifetime, this depends on that, this runtime has this behavior and thus, ... Fable seems to grasp this easily. I rarely had to explain business logic.
But it also feels dumb somtimes? I asked it to fix a bug where we wouldn't retry the creation of a resource after a timeout. It fixed it. I looked at the code and was skeptical. "Are you sure?" And it went "You're right, this is not correct." Then it took another turn and got it. Felt strange, like 2025.
It's slow. Oh my god is it slow. Now, I don't mind slow models that much if I can rely on them doing the right thing, which is what started with 5.3-Codex, but well, see previous oint.
It's expensive. Oh my god is it expensive. I have 3 Amp threads open right now that are at $704.27, $451.65, and $271.12. These are *not* outrageously large or crazy threads. I wouldn't have thought about their cost with any other model.
Those costs confused me, until
@nicolaygerold pointed out that I'm constantly busting the token cache. We're using the cheaper Anthropic cache writes with a 5min TTL. That means if you don't use a thread for 5min, then the next inference call busts the cache and costs *a lot*.
Now combine point 2 (sometimes it's not that smart?) and point 3 (it's slow) and I end up with multiple checkouts where I'm constantly waiting on a model but might miss when it's done and then once it's done I have to do a follow-up: cache bust russian roulette.
Since it's only Day 2, I'm sure I'll have more thoughts soon, but so far, my verdict:
Its smarts are overshadowed by its ergonomics and economics.