Real-time updates: Pusher, WebSockets, or Server-Sent Events? Which is best?

hey folks, i've been wrestling with how to implement real-time updates for a new feature and wanted to get the community's take. we need to push small data updates to thousands of clients concurrently. my initial thoughts were around using WebSockets directly, but then i started looking at managed services like Pusher and also Server-Sent Events (SSE). what are your experiences with these approaches? when did you choose one over the others, and what were the deciding factors? any hidden gotchas or performance considerations i should be aware of?