Software is like sex; it's better when it's free.

Comparing stream-up with gRPC transport:

- No gRPC libraries needed, better performance.
- Downstream is a separate GET request, no CDN traffic limit on gRPC applies.
- Has features like header padding, XMUX, upstream/downstream separation, and extra configuration sharing. It’s more mature.
= XHTTP’s advantages over WebSocket or HTTPUpgrade transports are numerous—no visible ALPN: http/1.1 signature and much more. By now, you’ve likely formed your own opinion.

when mode defaults to "auto," the behavior is:

- Client: If TLS H2 is enabled, use stream-up. If REALITY is enabled, use stream-one (if downloadSettings is present, also stream-up). Otherwise, use packet-up.
- Server: By default, accepts all three modes. If set to a specific mode, only that mode is accepted. Exception: specifying "stream-up" also accepts stream-one.

The most compatible mode for XHTTP—“packet-up” (packet-based upstream, streaming downstream)