Drupal 7 and PageSpeed
This is the PageSpeed section from my .htaccess:

&lt;IfModule pagespeed_module&gt;
    ModPagespeed on
    ModPagespeedEnableFilters extend_cache
    ModPagespeedEnableFilters collapse_whitespace
    ModPagespeedEnableFilters combine_css
    ModPagespeedEnableFilters move_css_to_head
    ModPagespeedEnableFilters remove_comments
    ModPagespeedEnableFilters inline_css
    ModPagespeedEnableFilters rewrite_javascript
    ModPagespeedEnableFilters insert_img_dimensions
    ModPagespeedEnableFilters rewrite_images
    ModPagespeedEnableFilters rewrite_css
&lt;/IfModule&gt;


Whilst there is a little overlap with the js and css compression, I'm not seeing any negative results. I've set Drupal 7 to aggregate and compress CSS and JS.

The site isn't particularly high traffic though.