Global Site Search and Marketpress


I have a multisite install and using Marketpress, and I'll need network wide search capability It seems like your global site search plugin will do the trick. However, does it query meta data or only tags?

I'm asking because I currently have added custom fields for key product information, and my understanding is these are added as meta data. If the plugin does not query meta data, would I be better off using custom taxonomies instead?