I just used three coats of polyurethane without sanding on the remainder of the house and there is not a visible difference. The window frames and stairs got a few swishes also.
Check out the shine!
|I hope you can see the shine|
|If you look closely you can see how the floor reflects on the ceiling in the attic|
|Compare the shine to the picture below|
|Before-Only the floor on the lower left had a coat of polyurethane|
Click on pictures for a larger view