Interesting stats from lensrental on their repair issues. I’d conclude that this is a pretty respectable resource.
The 17-55 IS EFS, 10-22 EFS, and the 100-400 IS L appear to be the most problematic. The 17-55 IS EFS seems to especially garner quality control complaints by users on forums.
on the other hand, it looks like there are some serious issues with Sigma as well, which can be read at this link:
