Passing is More Fluid and Usable
In addition to team mates giving better space for passes, the passing mechanics in FIFA 16 are more fluid and there is an option to deliver better placement and more powerful passes.
When you need to deliver a pass in a specific spot with speed, there is a new button combination that lets you make a faster, more powerful pass. When you do this you can split defenders in a tight situation. If you use this in the wrong spot the recipient of your pass will have trouble controlling it.
In my experience it is also easier to switch field position and lob passes work better in FIFA 16.