According to The Register. No real differentiation (AoE isn’t that good, and the Seagate/Hitachi network drives are going to completely obviate the need for such things).
We once used and sold Coraid to a customer. The linux client side wasn’t stable. iSCSI was coming up and was actually quite a bit better. We moved over to it. This was during our build vs buy phase. We weren’t sure if we could build a better box. After getting one and using them for a customer, yeah, we were very sure ours were better.
On the performance side, they never really had anything significant.
Such is life, I hate watching companies go down, even if they are nominally competitors.