I've only had the lockup thing happen to me once. It's not as a big of problem as it's made out to be. For every 1 person that has a problem with the lens, there could very well be many others that don't.
However, that said, I don't deny that Canon has been having some serious QC issues as of late... Even with their L lenses. I had to sort through 3 different copies of the 35L before I found one that focused correctly (1 was even really soft wide open) and is sharp wide open.