[Jedd]

It depends what problem you're trying to solve.

For inter-landmass traffic, my gut feel is bandwidth is the bigger concern.

The latencies we see now (as noted in TFA) are not that far from theoretical limits. I'd suggest responsiveness is best solved further up the stack -- and it's what most organisations have done / are doing.

Basically you don't want to run chatty protocols over high RTT networks, and people are slowing getting this ... but many orgs are stuck with HTTP, MAPI/MoH, SMB/CIFS consuming most of their WAN bandwidth.