United has its own Customs area , its pretty crowded when a full flight comes in ,
can take 10-20 minutes thru passport control, and I have never had my luggage waiting for me , even with priority tags (worthless).

Once past US Customs and out the door there is a place to leave your cleared luggage , but you are now down in the arrival area and will need to make your way upstairs and thru Security again.

Rally