Start with a task you repeat
Write down three jobs you actually do: turn source material into a client brief, extract decisions from a document, or prepare a presentation from research. Give each job a clear finish line. A useful result might be an editable document with checked references, rather than a convincing answer in a chat window. This keeps your evaluation tied to work you can recognise and inspect.
Use the same brief everywhere
Choose a small, non-sensitive sample and give each workspace the same instructions. Specify the audience, source material, required format and facts that must survive. Keep the prompt unchanged for the first attempt. Then allow one revision. Record which corrections were needed and whether the second attempt actually addressed them. This produces a more useful comparison than collecting unrelated impressive demos.
Measure the work after generation
A fast first draft can still be expensive if it takes a long time to repair. Track preparation, generation, fact checking, revision and export separately. Open the exported file in the application where you will really use it. Check formatting, links, tables and whether the result remains editable. Treat an attractive preview as an intermediate step until the final file works.
Check the plan in your own account
Before paying, confirm the billing period, currency, taxes, renewal amount and cancellation process shown to you. Record which features and model variants your plan includes. A marketing page may describe the entire product family, while a specific subscription has narrower limits. Test the allowance against a normal week of work, including retries and revisions.
Keep your decision reversible
Start with the smallest commitment that lets you test the real workflow. Keep original documents, prompts and final exports outside the service. Decide what would make you switch: missing references, unreliable exports, unclear usage charges or a process that still needs too much manual repair. Revisit the choice when your work changes, rather than every time a new feature is announced.