Sometimes the hard part of arriving on that flight is immigration. I've had several times where immigration didn't have any lanes open and had to stand in line there for 15-20 mins just waiting for it to open. Then they like to use two baggage claims. I've never had any problems with customs knock on wood, there. Always breeze right through. Maybe if you miss your connection you can blame it on the airline and add a domestic segment and more miles, not that anyone would ever want to do that.