Yes I got one too for what was probably novelty value. After a busy couple of weeks with it, it's gathering cobwebs on the shelf. As mdm041 mentioned, it's a mighty expensive body-cap.
After doing side by side tests against the Sigma 50 f/1.4 and the 24-105 at comparable focal lengths, the novelty value quickly faded. I guess I'll give it to my daughter to help make her old 30D more school bag sized...
-PW