Well, if the config variables are accessed like, all the time every time for every page load, then it is probably faster to do your config like this:
class CONFIG
{
const DB_HOST = 'blahblah';
// etc..
const DEFAULT_PAGE = 'blahblahblah';
}
echo CONFIG::DB_HOST;
That's the way I prefer, but my goal is to cut down on queries and leave things to the php cache to handle.
I guess it all depends on what you call config info and what scripts need it for which users.