Google Gemini 2.5 Pro-Exp: The UI specialist with identity issues
Google’s Gemini 2.5 release ships a one-million-token context (two million promised) and is currently free to use in many places (I’ve yet to be charged for API calls). It shines at UI work and is the fastest model I’ve used for code generation. The catch: If your repo uses an API that changed post-training, Gemini may argue with your “outdated” reality—sometimes putting your reality in scare quotes. It also once claimed that something in the log wasn’t possible because it occurs in the “future.”
Use it for: Dashboards, design-system polish, accessibility passes, quick proof-of-concept UIs.
Watch out for: Confident but wrong API calls and hallucinated libraries. Double-check any library versions it cites.
OpenAI o3: Premium problem solver, priced accordingly
OpenAI’s o3 (the naming still confuses people who expect “GPT”) is a research-grade reasoning engine. It chains tool calls and writes analyses, and it will pore over a 300-test Jest suite without complaint. It is also gated (I had to show my passport for approval), slow, and costly. Unless you’re on a FAANG-scale budget or you’re unable to resolve a bug yourself, o3 is a luxury, not a daily driver.
