Hot plug SATA external drive

AMS Electronics has an external harddrive enclosure that takes a SATA drive and interface with the PC on either a USB2 or SATA interface. I have been using drive enclosures that has the USB interface and know that they are hot pluggable. But does this hot pluggable also apply to the SATA interface? I mean when the SATA connection is made with this enclosure, as far as the computer is concerned, the physical external drive is internal. Therefore, all the properties of SATA apply to the enclosure if I use the SATA interface. This begs the question of if I want to turn on or off this enclosure while it is using SATA connection, do I simply turn off the power to the enclosure or should I shut down the PC first.

I heard that there is still some debate as to whether SATA is hot pluggable. This is still a controversy even with SATA II. To make things more confusing, the organization that oversees the SATA specs now comes out with SATA 2.5. (There is also a SATA 2 spec that is not to be "confused" with SATA II). As far as I can tell, any drive or device that has the SATA 2.5 logo on must be hot plugable. If this is true, then all the non-SATA 2.5 devices are not really hot plugable.

As with all newly emerged standards in computer, the first version is always a mess and confusion. It's particularly bad with the SATA standard. So bad in fact that the organization that was in charge of the spec of SATA 1 changed its name so not to be confused with its former self even if it's the same organization! Even with SATA II, things are a mess because some of the "SATA II" or "SATA 2" drives because some supports NCQ but not 300MB/sec and some support the latter but not the former. Now, the SATA organization has put its foot down and demands that any drive or controller with the label SATA 2.5 must satisfy both NCQ and 300MB/sec maximum throughput.