People ask me all the time: "Which AI should I use?"
The answer is: "What are you trying to do?"
In 2026, the "Big Three" have specialized. I use them all, but for very different parts of the Business Analysis lifecycle.
My Use Case: Writing Requirements & Documentation.
Claude (especially the 3.7/Opus versions) has the best "ear" for tone. It doesn't sound like a robot. It sounds like a senior consultant.
Why I love it: It has a massive context window. I can feed it an entire 100-page PDF of legacy documentation and ask, "Where are the contradictions?" It finds them. Every time.
My Use Case: Technical Feasibility & Workspace Integration.
Because Gemini is baked into the Google ecosystem, I use it for "Agentic" tasks. "Look at my calendar, find the meeting notes from last Tuesday, and draft a follow-up."
Why I love it: It excels at code. When I need to verify if a developer's estimate of "3 weeks" is accurate, I ask Gemini to scope the code. If Gemini says "3 hours," I know I need to have a serious conversation.
My Use Case: Brainstorming & Quick Ideation.
GPT is still the "Swiss Army Knife." It's fast, it's good at conversational back-and-forth, and it's great for breaking a writer's block.
Why I love it: The reasoning models (o-series) are fantastic at logic puzzles. I use them to stress-test user flows. "Act as a malicious user trying to break this signup form. What would you do?"
The Takeaway:
Don't marry one model. They are tools in a toolbox. You wouldn't use a hammer to turn a screw.
