This review is part of a larger series of LinkedIn newsletters titled The Human Side of AI: Cutting through the AI noise to show you how AI can be a powerful tool for your creativity, efficiency, and strategy.
Lex is an AI-powered writing assistant that helps market researchers turn complex insights into content that lands with B2B audiences. Grammarly and Writer are useful, but they mostly police what you’ve already written. They don’t help you reshape a draft from a different angle. Lex does. It works as an AI collaborator inside the writing itself, which makes synthesizing research into clean prose easier.
What’s new since we last reviewed this tool in 2025: Lex has moved the best AI models into the editor itself (GPT-4.1 and Claude 4 Opus and Sonnet), added real-time collaboration and a paid Lex Teams tier, shipped an iOS app, and introduced one-click web publishing along with customizable style guides. The Power rating moves up as a result.
Lex takes the friction out of turning detailed research into a narrative that reads well. It works like a co-writer, offering suggestions or drafting a paragraph from a short prompt. The biggest change since my last review: the strong models now live in the editor instead of sitting in a tool you switch over to. You can draft against Claude 4 Opus or Sonnet, or GPT-4.1, and move between them without juggling separate subscriptions and logins. For researchers who care about which model shapes their prose, that control matters. You can push on an idea or tighten a paragraph without surrendering your voice or the insight underneath it.
Lex also runs a set of writing checks on your draft: grammar, brevity, clichés, readability, passive voice, repetition, and more. A checklist pops up and walks you through each one. For market researchers writing for B2B audiences, where clarity and precision aren’t optional, that structure earns its keep. It’s more actionable than Grammarly’s underlines.
A few other features worth calling out:
- Show AI-written text. It marks which lines are yours and which came from the AI.
- Native model selection. Pick the model you want, Claude 4 Opus or Sonnet, or GPT-4.1, and ask it for feedback, a rewrite, or a fresh angle without leaving your draft.
- Audience Check. Describe who you’re writing for, and Lex tailors its feedback to that reader.
- Collaboration and Teams. Sharing a document is free, with live co-editing, comments, and version history along the lines of Google Docs. If a research team is co-authoring a report or holding to a house voice through custom style guides, the paid Lex Teams tier adds shared folders and more structured group work.
- Mobile. There’s now an iOS app plus mobile web, so you can capture or polish a draft away from your desk.
Where Lex still falls short: it’s a writing tool, full stop. If your process depends on a traditional word processor, with heavy formatting and true track-changes redlines for client review cycles, you’ll feel the gaps. Lex leans on comments and version history instead. It also skips the template libraries and SEO tooling that marketing-first tools ship, which suits research writing fine and rules it out if that’s what you needed.
Ratings:
| Dimension | Rating | Rationale |
|---|---|---|
| Usability | 5 / 5 | Clean, distraction-free editor; the AI stays out of the way until you want it. |
| Power | 5 / 5 | Top models (Claude 4 Opus and Sonnet, GPT-4.1) built in, plus custom style guides, put it well past a grammar checker for drafting and structuring serious work. |
| Flexibility | 4.5 / 5 | Collaboration, Teams, mobile, and publishing widen its range, but it’s still a writing tool without a full word processor’s formatting or redlines. |
| Cost | 5 / 5 | Real free tier; Pro is a flat $18/month with no per-word credits or overage fees. |
In Sum:
For market researchers, Lex works as a writing partner rather than one more grammar checker. The strong models sit in the editor, and the feedback is tuned to whoever you’re writing for. Teams can draft together in the same document. What keeps it worth using is that it never takes over: you stay in control of the model and the voice, which is what research writing actually needs.
Last updated: 7/7/2026