Judge it on your work, not on benchmarks
Public benchmark scores move monthly and correlate loosely with whether an assistant is useful to you. The reliable test takes an afternoon: collect five tasks you genuinely repeat, run them through two or three assistants on their free tiers, and compare. Teams that do this almost always pick a different product than the one the leaderboards suggested.
The ecosystem you already pay for is a real argument
If your company runs Google Workspace, Gemini reads your Docs, Sheets and Gmail without an integration project. If you run Microsoft 365, Copilot does the same across Word, Excel, Outlook and Teams. That native access is worth more day-to-day than a modest quality edge, and it is the single most common reason our reviewers give for their final choice.
Understand what "unlimited" means before you buy
Nearly every consumer tier here advertises generous limits and enforces quieter ones — message caps on the strongest models, slower queues at peak, smaller context windows on cheaper plans. This is not dishonest, but it does mean the $20 tier and the $200 tier can behave very differently on exactly the work you bought the tool for. Test at your real volume during the trial.
Data handling is a procurement question, not a feature
Check three things before rolling anything out: whether your inputs train the vendor's models by default, whether there is an enterprise agreement that turns that off, and what the retention window is. The answers differ meaningfully across the five products here, and they are far easier to establish now than after a team has pasted six months of customer data into a chat box.
