Private label parts are just that...private label, IE sourced from someone else. Quality varies greatly from not so great to practically as good as name brand, just with a shorter warranty and hopefully lower price. That's true across the board. You may get a great Duralast part, or a garbage one depending on where they got it from. You may get a great Driveworks part, or a garbage one, depending on where they got it from. They may sometimes get the part from the same manufacturer, built to the same price point, and there is no real difference. Reboxed/rebranded parts are just that.
Sometimes reboxed/rebranded parts can surprise you...I opened up a "BWD" temp sensor or something for a Honda Accord, and it had actually been boxed still in the Honda bag...it was an OE Honda part, still in the Honda wrapper, just thrown in a BWD box. I have also seen a BWD crank sensor for a Ford 6.0 PSD that had the Ford part number and only the Ford part number engraved on it...appeared to likely be a Ford part that had simply been reboxed. BWD isn't exactly a house brand/private label, but they are only a step above.