It surprises me that the SYN attacks are being mitigated on the machines themselves; I was under the impression that this is typically done with hardware firewalls that offload the TCP handshake (thus filtering out spoofed SYN packets and other connections that the remote machine doesn't intend on actually establishing).

It does seem like doing it on the target machine will reduce latency a bit, though, since the hardware TCP offloaders usually repeat the TCP handshake (this time to the actual server) after confirming that it's valid.