Tested Groq, OpenRouter, and Gemini as API backends for a project. Same task, three different experiences. Gemini — solid output quality, no complaints there. Where it fell short was cost and speed once I actually started pushing real usage through it. OpenRouter — the appeal is obvious: one API, access to a ton of different models. But that flexibility comes with its own overhead, more to manage, more to think about than I expected. Groq — this is where I landed. The speed difference is honestly not subtle. If response time matters for what you're building, it's hard to go back once you've felt it. None of these are "bad," they're just built for different priorities. Cost, flexibility, or speed, pick what actually matters for your use case instead of just going with whatever's trending. Which one are you running right now, and has it held up as you scaled?