The landscape maps onto three tiers by coverage, and 60 users sits exactly where the tiers genuinely compete, so the map with honest edges:

The native tier, Microsoft's Google Workspace migration built into the Exchange admin center: batch migration of mail, calendar and contacts driven from the 365 side, authenticated against Workspace through a service account you configure per Microsoft's walkthrough, running delta passes until cutover. Free, supported and the default answer at your scale, with its honest edges being the service account setup ceremony on the Google side, mail calendar contacts as the coverage boundary and Drive files explicitly outside it, migrating separately through Microsoft's Migration Manager for Drive to OneDrive when the files matter, which they usually do.

The per user tier, GWMMO and manual IMAP: Google Workspace Migration for Microsoft Outlook runs on each user's machine pushing that one account into 365, and plain IMAP batches move mail only as covered in the neighboring migration threads. Honest position at 60 users: the fallback lane for stragglers and special cases after the batch runs, rather than the plan, per user tooling multiplied by 60 being how weekends disappear.

The product tier, migration platforms including SysTools Migrator among the vendor category: single operation coverage of mail, calendar, contacts and Drive together, scheduling, per user reporting and rerun controls, the tier earning its license when Drive volumes are serious, timelines are compressed or the native tier's two separate migrations and service account ceremony read as more risk than budget. The evaluation questions that separate vendors quickly: Drive permission fidelity into OneDrive and SharePoint, shared drive handling and what the per user reports actually prove when a user disputes completeness.

The 60 user recommendation shape most projects land on: native tier for mail calendar contacts plus Migration Manager for Drive when timeline permits the two track work, product tier when Drive complexity or the calendar's density argues for one operation, and the per user tier held for the stragglers either way, with the pilot batch of five users this week teaching more than another week of tool comparison.