I have and use both Claude Code and Gemini CLI, and still don't consider Gemini worth starting for coding except to review Claude's output in critical commits (on a security boundary, maybe broad refactors, etc.), though I try side-by-side every now and then just to see the state of things. I also use Gemini Pro in a security scanning harness to act as a second set of eyes, but Opus is better at finding security bugs than Gemini, so I don't know that it's accomplishing anything beyond just using Opus.

Gemini Pro 3.1 for agentic coding is still clumsy. It chews a lot, has a harder time with tools and interacting with the codebase. I haven't tried any 3.5 version, yet, though. The benchmarks look promising.

I'll note I like the Google models' prose better than any others at the moment, though. Even the small open models (Gemma 4 family) have excellent prose, relatively speaking, that doesn't stink of the LLMisms that I find so annoying about OpenAI (especially) and Anthropic models. So, I'll probably start using Gemini for writing API docs, even if all code is Claude.