(Again IIRC some arguments, such as which column to sort on by default, are the actual integer index into the columns array -- i.e. pass a 1 to sort on the second column. The last time I saw anything like this was when I was looking at Quake3 source, written in C!)
However it does the job well once it's all set up and for a long time it was miles ahead of any other option. Only ExtJS and YUI grids are/were better but those require large frameworks and a number of assets to be in place. I would never advise someone to use it today though, I have to say. I used it once for a critical project and in retrospect I would have rolled my own, despite time constraints.