It's about a month since I got hold of this card and it has been pretty good. The "save" time seems no different to the Kingston and other SD cards. I am using it in a Canon 300D that usually takes compact flash cards, so I have a CF to SD adapter as well.
It is very easy to setup and works pretty well. What is a surprise is that when the camera is on and the laptop with the Eye-Fi software installed that there is a delay before the pictures start to arrive.
In the first blog I posted a pic of the photos arriving. As well as a delay in the first one arriving, they arrive in batches.
I took a small batch at the Ashford Classic Motorcycle Show, and once home, it took four or maybe five bursts to get the dozen or so photos down, and better part of 25 minutes.
The system's "Endless Memory" is turned on but as yet, with a card that holds over 900 photos, I've not got to the point when it starts to overwrite the oldest ones.
All in all it has been a success.