Cross country point to point link question

[Petter.Bruland at allegiantair.com (Petter Bruland)]

Question for someone with some experience with long haul links (Las Vegas -- New Jersey)

[Cisco 4510 - SVI-VLAN x]---trunk---[Nexus5K LH optic]===fiber==={carriers across country}===fiber===[Nexus5K LH optic]---trunk---[Cisco 4510 - SVI-VLAN x]

We have two circuits, one that is the same vendor from east to west, and the other circuit is a two vendor deal. Both circuits are 1 Gbps with around 67-70 ms delay.

As soon as we had the links turned up, our SAN guy started complaining about poor throughput, asking us to throw in a couple of wan accelerators.
He was seeing a max throughput of around ~200 Mbps.

Question: For a long haul 1 Gbps link with 67-70 ms delay, would  installing a pair of wan accelerators make a big difference? 

Thanks,
-Petter Bruland