How useful is HL for a GM?

[fenriswolf]

I just started up a Pathfinder game (Rise of the Runelords) for my group and was wondering how useful HL would be from a GM point of view. I can see where it would be really helpful for players to keep track of their characters but what specific uses does it offer for a GM? I don't plan on creating my own character classes or custom feats and really only plan on using the ones already written. Any Pathfinder GMs care to add their 2 cp's?