Below are some pics of what it looks like in our Master Bath when the vent is open and a pic of the shallow boot duct work. Now you could probably live with just closing the slats, but why would someone want too? It affects overall airflow and efficieny. You're making a big investment and paying for the house for 30 years. It should be perfect, right?
|This is how it looks when the register is open|
|Shallow boot sloping. (It should be at least an inch deeper on left to allow open register and sit perfectly on top)|
|Another picture of register when slat is open.|