Looks like Global Search only searches on the name field? Would be preferable if there were a search option that searched all text including comments, and sub-tasks. I often update a task with a comment or sub-task, e.g. "remember to inform so-and-so after this is complete". Later on I may think to myself - 'what was it I was going to tall so-and-so...?'. If I can search on his name it will allow me to find the item. This is not limited to names, same is true for any number of keywords.