PHP Session vs vBulletin session table

[vooood]

I was wondering what would be the most efficient thing to use - PHP session or the vBulletin session table?

I'm asking this because I'm working on a game plugin for vBulletin that needs sessions. There are already a lot of DB requests and I was wondering if adding pure PHP sessions support for a few basic things will save me a lot of DB requests - for example character name, description, etc.

The questions is will this help me to achieve better performance or is it the "same" as extending the vBulletin session table?