I sand the entire homes ceiling between coats.  Notice the even look.  When standing in the loft looking towards the outside, the ceiling is flawless. It looks very rich and deep. The grain is full and stunning. This is how all wood ceilings should look. Its hard work but worth every penny. When sanded, the knots in your ceilings fill in and the wood looks smooth and beautiful.
The ridge beams have all been sanded tight to the ceilings so dust doesn't stick as easily and so dust can be vacuumed or dusted very easily years later. Interior finishing is usually good for years and years. We think ahead for the customer! Do it right the first time.