Hard disagree. I use 3.8 flash in Antigravity a lot, and thoroughly prefer it to most Pro-class models. It's really fast, and I've had it make crazy progress on compiler-like problems that previous models including Opus simply failed at. On ultra plan you can have it going for hours, and make incremental progress with good prompting for review interrupts. It solved a problem I couldn't solve for weeks in under 6 hours. 10k LOC total. The harness and test suite is key.
This is my exact experience with the model - https://x.com/ThePrimeagen/status/2095565354726502683
And it just BURNS tokens like crazy.