For all of my official ubuntu updates (main universe multiverse restricted) I use an Israeli mirror of the ubuntu repositories, with one exception: for the security updates I use http://security.ubuntu.com. The Israeli ISOC mirror also provides the security updates.
What are the pros and cons of using a mirror instead of the official repository for security updates?
Are there any real security concerns I should consider by moving my security updated to a mirror instead of the official server?
What I can think of:
Security-wise I wouldn't worry that much, since packages and lists are all GPG-signed.