I also use a separate entrance and it works very well for my basement daycare.

The stairs to my daycare is right by the door, the parents are able to come straight down to daycare (I have a chime on the door to let me know when the door is opened). It works well especially if the parents are running late for drop off or running early for pick up, as it enables me to continue my programming with the children and not have to worry about being on the main level for pick up and drop offs.

I also like that my family has some normalacy as during drop off time my girls are getting ready for school and during pick up my hubby is up making supper, etc, this way, my family isn't being interupted and they can continue with their normal routines.