I used my $200 free fable 5.1 credits to build a WhatsApp sticker maker, it created a version I was not happy with, but it burned the 200 in one sitting. Node.js app, vue frontend, etc.
I didn't used the project a lot since I kind of hate it on how much was spend.
Last week I used just a little bit of my $20 pro account to build a replacement with rust end to end, just to gain some experience with the rust hype. Very happy with the result, not perfect but snappier, and even better: a single executable, I no longer need to fire up a backend and front service separately.
What model did you use for the rust rewrite? Opus 5.5? I mean it seems pretty crazy that you had such different results.
I use Sonnet 5.5 and Opus 5.5 both on Medium to produce apps in Rust/Tauri all day every day on a $20 Pro sub, and absolutely these two models do a great job with that stack. I rarely run out of weekly credits, unless I use Opus 5.5 on high or ultra code. Medium does the job 99% of the time. Fable is good, but it'll never be as good as Opus when well prompted and with some iteration. I see Fable as a preview of what the next model will be able to do, but it's really not a good production model unless you have a lot of cash to burn.