I think WordPress TOTALLY SUCKS in this regard.
I’m also using Load Balanced install, and I happen to have my own CDN with image optimizations and stuff.
I have 8 servers with my nginx proxy cache and 4 servers with apache+wordpress in two data centers using a central master-master database and I JUST NEED an option to link img src uploaded files with a different domain – HINT: using upload_url_path.
This sucks and having to use a plugin to save the post with regex is totally lame when the option to use a different domain with $upload_url_path is already there.
4 cents