We do not use JDS either and I just recently started using the load sharing feature. It seems to work okay overall, although I have noticed a few package deployments fail because of "package not found" errors. We are using Casper 9.7.
As far as functionality goes, it will randomly grab packages between different servers when deploying to multiple computers. It isn't true load-balancing in that sense, but works well enough when doing larger deployments. I will try to reply back to this thread if/when I find out what caused the fluke deployments to fail.