mercutio:
Well yeah - but I think there is actually a lot of hidden latency on the internet now days. Some people say that ping/traceroute is inaccurate cos icmp is depriortised. But sometimes whole tcp streams can be deprioritised (or go across higher latency path), rate-shaped(or have enough packet loss to limit transfer speeds below that of which the connection accessing). You can do a traceroute, then do an actual connection and end up on a different path.
So you may ping and get 125 msec ping, then do a tcp connection and get 135 msec.
But this kind of traffic shifting could become even more common with "bulk" traffic being pushed through Australia and interactive traffic being pushed straight. Or low-value customers being pushed through Australia.
ICMP should have same priority as most other traffic. Besides which, this is only an issue if the slowest link is nearing saturation.
TCP introduces its own overheads, and packets will be bigger, so you can't really compare TCP ping with ICMP ping.
Truth is that as many people have pointed out, on international traffic most of the latency is purely due to physics and cannot be reduced in the context of our current understanding of physics.