Does Unicon have experience load testing Sakai?

Yes, Unicon has experience with load testing Sakai.

Unicon collaborated with the University of Michigan to performance test the Samigo assessment tool at an on-site testing session at the University of Michigan, as presented at a Sakai conference. See especially the load test report resulting from this effort.

Unicon also worked with Wiley to complete performance testing of Sakai 2.5, as documented in Sakai's wiki. See especially the test plan document and test results report.