There are factors favoring SPDY, such as fewer roundtrips thanks to pipelining, or header compression removing the uplink as a bottleneck. There are factors fav

There are factors favoring SPDY, such as fewer roundtrips thanks to pipelining, or header compression removing the uplink as a bottleneck. There are factors favoring HTTP, such as being less vulnerable to head of line blocking, higher effective congestion/receive windows, and a smaller reduction on the effective congestion window from a single packet loss. Without testing, it's not at all obvious which set of benefits is actually more significant in the real world. But if I'd had to guess, I would have expected a reduction in roundtrips to be the dominant factor. So yes, I'm a bit surprised.