It doesn't support CF+, mainly because the connector is a different size but also because CF+ cards do not always support the True IDE mode required. The largest CF card I have found is 1 gig. In tests I have seen no slowdown although it is of course all subjective. Hope that helps.
It's not ideal for swapping files between computers as it's an internal add-on, unless you want to open up your kit on a regular basis. It would be useful to quickly test the boot drive between several machines for testing purposes however.