My only complaint with the Bike Packers is that the top hood does not "float" and allow you to expand capacity on times when you need a bit extra (like after buying food, etc.). There is a big storm-collar sort of extension at the top inside, which lets you expand the capacity, but then there is no way to buckle the actual outside top part back down. Well, complaint #2: the small, flat outside pocket is basically unusable when the main pannier is packed full (hard to get anything but papers or maps in or out of there).
That said, I like mine (have two sets), and they have held up well since we first bought them around 20 years ago. I have an older pair and a newer pair. There's plenty of room in them.
Also I agree that the Ortlieb rack duffle is really handy to have.