There’s obviously a problem, maybe with your setup or settings, if the Sammy only runs (burns or reads?) at 2.4x, you may like to investigate that with our help before returning it.
However, the Pioneer I was thinking of is the 115(D). I also have that drive and it’s very good.
It’s true that Pioneers aren’t reliable scanners, you may like to keep your Litey around for that job. As for Samsung, as the FAQ says, whether they’re good DVD scanners or not depends on your drive.