Quick Verdict
Choose Guru if the company's main problem is answer trust. Guru is strongest when teams need verified knowledge, citations, permission-aware answers, auditability, Slack and Teams delivery, browser access, and a path to connect governed knowledge into external AI tools through MCP.
Choose Glean instead if the priority is broad workplace search across many apps. Choose Slite if the team wants a simpler knowledge base plus enterprise search bundle with lower adoption friction.