February 14, 2015
I've found this hood to be excellent. The build quality is great - with small buttons used to release the lock and a beautiful machined aluminium ring at the base of the hood. I've paid a lot more than this for Canon hoods in the past that haven't been as nicely made.
I have had no issues with the hood falling off unexpectedly.
August 04, 2014
It works fine when it's on but it falls off way too easily. If there were an alternative I'd use it. On my second one I intend to use a lens cap holder. There are descriptions on the Internet of beefing up the spring.