I have two old Duxtop burners one failed after many uses and they worked so well I decide to buy this new dual burner model but it doesn't heat up as fast as my old single burners. Not sure if this is by design but I noticed it doesn't boil water as fast and pans don't heat up as fast. one example i noticed is when I tried to pop popcorn in a pan and it wouldn't pop even on the highest setting. I pulled out one of my old working single Duxtop and that one starting popping very fast on a much lower heat setting.
Will be contacting Duxtop on this issue and hope that its just a defected unit.