I'm just trying out a new method to optimize vBulletin's front end scripts and CSS. It's still a work in progress but these are the results I have seen on my test site (www.wirelessforums.org)
Without GZIP
Base VB (v3.6.8)
vbulletin_global.js - 43.8KB
vbulletin_menu.js - 17.8KB
vbulletin_read_marker.js - 6.7KB
vbulletin_md5.js - 9.6KB
JS total - 77.9KB
css - 5.7KB
Using minify
vbulletin_global.js - 23KB
vbulletin_menu.js - 10.4KB
vbulletin_read_marker.js - 3.3KB
vbulletin_md5.js - 6KB
JS total - 42.7 (45.1% savings)
css - 4.1K (28% savings)
With GZIP
Base VB (v3.6.8)
vbulletin_global.js - 12.5KB
vbulletin_menu.js - 4.7KB
vbulletin_read_marker.js - 2KB
vbulletin_md5.js - 3.3KB
JS total - 22.5KB
css - 1.3KB
Using minify and GZIP
vbulletin_global.js - 6.9KB
vbulletin_menu.js - 2.7KB
vbulletin_read_marker.js - 1KB
vbulletin_md5.js - 2.1KB
JS total - 12.7KB
This is an extra 43.5% savings on top of GZIP. A total of 65.2KB (83.7%) savings from the original.
css - 1.1KB
An extra 15.3% savings on top of GZIP. A total of 4.6KB (80.7%) savings from the original.
This is a huge improvement over the original file sizes and speeds up rendering of the page quite a bit. The new method doesn't require you to download JS replacements for each version of vB, instead it works off the existing files. Hopefully this will silence the people who complained about copyright/piracy issues with me distributing the JS files (even though they're distributed to every browser that downloads the page).
I'm also looking at some other ways to speed up rendering as much as possible. Stay tuned for downloads and a full write up.