Updated: Nov 22, 2025

Claude 3.5 Sonnet as My AI Strategy Partner: When I Use It Instead of ChatGPT

TL;DR

  • Claude 3.5 Sonnet is my “strategy and long‑form” model. When I need clear thinking, structure, or nuanced writing, I open Claude before ChatGPT.
  • It’s especially good at multi‑step reasoning, outlines, and rewriting messy drafts into something coherent and calm.
  • Weak spots: It’s slower than lighter models, sometimes overly cautious, and not always the best for super‑short, snappy copy.
  • Best for: Solo founders who want an AI partner for positioning, product strategy, content, and decision‑making—not just quick answers.
Tool usedClaude 3.5 Sonnet
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Why I Added Claude 3.5 Sonnet to My Stack

I already had ChatGPT Plus. I wasn’t looking for “another chatbot.”

What I wanted was something closer to an AI thought partner—a model that could sit with a long prompt, understand nuance, and help me think through decisions for my one‑person business.

Claude 3.5 Sonnet ended up filling that role.

How I Actually Use Claude Day to Day

Roughly, I use Claude 3.5 Sonnet for four things:

  • 1. Outlining complex articles, emails, or landing pages.
  • 2. Rewriting messy brain‑dump notes into something my future self can understand.
  • 3. Thinking through product and positioning decisions (“Talk to me like a co‑founder who challenges my assumptions.”).
  • 4. Summarizing long documents (strategy docs, transcripts, customer interviews) into clear bullet points.

When I need speed or lots of tiny questions, I still reach for lighter models. When I need depth, I open Claude.

Strength 1: Calm, Structured Writing

Claude’s writing style is naturally calm and organized. If I paste in a chaotic draft and say, “Turn this into a clear, structured article with headings,” it usually nails the outline on the first try.

As a solo founder, that’s huge. I can brain‑dump in plain language and then let Claude transform it into:

  • A newsletter outline.
  • A landing page with sections, sub‑heads, and CTAs.
  • An internal strategy memo.

Strength 2: Long‑Context Reasoning

Claude 3.5 Sonnet is comfortable working with big prompts: multi‑page notes, whole conversation histories, and detailed specs. This long‑context reasoning makes it ideal for:

  • Summarizing customer research docs and pulling out patterns.
  • Comparing two or three competing ideas and listing trade‑offs.
  • Helping me design product onboarding flows or pricing pages step by step.

It feels less like a “question‑answer machine” and more like a quiet collaborator you can think out loud with.

Where Claude Isn’t Perfect

Claude is not my all‑purpose default.

  • It can be slower than smaller models, especially on big prompts.
  • It sometimes gives too careful answers when I just want a bold suggestion.
  • For very short, punchy marketing copy, I often get better first drafts from a lighter, more “aggressive” model.

So I don’t try to force Claude to do everything. I treat it as a specialist: the model I call when I need clarity, reasoning, and structure.

Claude vs ChatGPT in My Workflow

People always ask, “Which is better, Claude or ChatGPT?” My honest answer: it depends what you’re doing.

In my stack:

  • ChatGPT Plus is my “Swiss Army knife” for everyday tasks, quick code, and generic brainstorming.
  • Claude 3.5 Sonnet is my editor‑in‑chief and strategy partner when I’m working on something important and don’t want it to feel generic.

What This Means for a One‑Person Business

As a solo founder, I don’t have a board, a strategy team, or a content editor. I have:

  • Me.
  • My tools.

Claude 3.5 Sonnet effectively gives me a patient, structured thinking partner I can lean on when making decisions or shipping important writing.

If you’re expecting fireworks, you might be disappointed. But if you want a model that helps you think better and write clearer, it earns its place in the BUILD stack.