This card works well for fixed installations. But if you intend to use eSATA docks where the target drives come and go the Mac OS X drivers are buggy. The effect of powering down or unplugging a drive connected via this card is that an internal data structure in the OS kernel is left dangling which causes a several minute blue-screen delay when logging out or shutting down.
I'm a software developer and have sent several bug reports with loads of diagnostics but after 4 months nothing has been done.
Obviously, if I'd known their software was broken I would not have purchased this product.