Quick, compatible and works with 50D + Eye-Fi X2

This adapter works with (m) a Canon EOS50D (latest firmware) and the Eye-Fi X2 card (firmware) in my case, the 4GB Connect X2.

I've also tested it with my 400D, also here does the transfer of the files, but I have very often corrupt data, both over WiFi and on the map itself. Sporadic and CF card error.

With the 50D it is functioning properly, both the transmission and storage on the card. The card can also be formatted easily on the camera.

Who is expected miracles from the adapter but disappointed: The field strength of the Eye-Fi card inherently very weak, in the adapter and the camera is all even more subdued.
Since the card slot is located just below the hand is still the natural enemy of WLANs to - water.

More than 3 meters to the access point or iPad are not in it - as long as you hold the camera in hand. Lying on the table to reach ever 5-8 meters.

Who is looking for an adapter to its Eye-Fi X2 can operate in a 50D safely access, the 400D is not working well.
The bottom line is - at least to my knowledge - the UDMA support - when the camera UDMA may also runs the Eye-Fi card. Important to know: CF UDMA cards are backward compatible, ie just because a UDMA card running in your camera, this does not mean that the camera also can UDMA.