This came from a Tech Admin for one of our clients (non-sports site). Figured that it would be incredibly informative to share with everyone else.
NOTE: Even though this mentions the Drupal software package, the answer is applicable to any software package/content management system used within our hosting network.
xCache is already enabled on the backend vServers, so all PHP code is opcode cached already.
The Load Balancer will serve the minified versions unless the software package you use creates the files in PHP and adds weird variables at the end (such as filename.php?foo=bar).
This also means that you shouldn’t need to implement any additional or special caching protocols within your own scripts unless it’s absolutely necessary.