While considering the possibilities of adding an eSATA port to my iMac, I am also investigating eSATA solutions for my MacBook Pro. Since I have an ExpressCard slot, the logical choice is to pick up one of the many ExpressCard eSATA adapters. But it looks like the options aren’t all that great: The SiliconImage chipset used in many is full-featured, but the drivers and hardware implementations are buggy, while the older JMicron controller is cheap and simple but lacks many desirable features.
