We are finding the global search function less and less reliable. This is a big problem when it comes to preventing data duplication. It's also a big frustration to users.
We use ZohoCRM ourselves so that we experience what our clients do. I've done several searches for contacts that do not show up in any of the search results, but are in the database. I can get to them through the account. What's even more disturbing is that I'm the contact owner.