It's just windows. You put roughly where you want them when you need them to have what you want visible. They stack. If one is out of your sight and you need it, you use the list or expose to find it and move it where it will be useful. It's like manipulating documents in the physical world except it's always easy to find a window in your stack of windows. It's a very natural flow.
Tiling is the solution imposing an unnatural cognitive burden on the user. With tiling you need to constantly think about exactly what you want to see, where you want your windows and you constantly need to fiddle with the arrangements and spend time preemptively positioning your windows. It gets very annoying to me as soon as I want more than one full screen window.