Oh yeah, I forgot to mention. Like you, I also notice a large difference in iSCSI performance when using OpenFiler. This despite using the same hardware and both being based on kernel 2.6.25.

Total write bandwidth for 4 clients: 350MB/sec
Total read bandwidth for 4 clients: 112MB/sec

That is using the same round-robin bonding as I do in Open-E.

No idea why. I like Open-E too much anyway now!