Thanks for this. Also applied these htaccess rules which have helped a lot...
<IfModule mod_expires.c>
ExpiresActive On
ExpiresByType text/html "access plus 7 day"
ExpiresByType text/js "access plus 7 day"
ExpiresByType image/gif "access plus 7 day"
ExpiresByType image/png "access plus 7 day"
ExpiresByType image/jpg "access plus 7 day"
ExpiresByType image/jpeg "access plus 7 day"
ExpiresByType image/ico "access plus 7 day"
ExpiresByType text/css "access plus 7 day"
ExpiresByType text/javascript "access plus 7 day"
ExpiresByType application/x-javascript "access plus 7 day"
</IfModule>
<IfModule mod_deflate.c>
SetOutputFilter DEFLATE
BrowserMatch ^Mozilla/4 gzip-only-text/html
BrowserMatch ^Mozilla/4\.0[678] no-gzip
BrowserMatch \bMSIE !no-gzip !gzip-only-text/html
# Don't compress images, movies or zip files
SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png)$ no-gzip dont-vary
SetEnvIfNoCase Request_URI \.(?:exe|t?gz|zip|bz2|sit|rar)$ no-gzip dont-vary
SetEnvIfNoCase Request_URI \.(?:avi|mov|mp3|mp4|rm|flv|swf|mp?g)$ no-gzip dont-vary
<IfModule mod_headers.c>
# properly handle requests coming from behind proxies
Header append Vary User-Agent
</IfModule>
</IfModule>
Will work on the partial cache soon, just need to work out what elements can be cached like that. Also setting up a varnish server as a test.
Thanks again