I definitely would not describe it as “heavy” though there are all-plastic ones that are lighter (flimsier). When he says “built like a tank” he is correct - this won’t break easily. But I definitely would not consider it to be heavy. Just sturdily built.
His admitted ignorance as to what comprises a “semi-weighted” keyboard caused him to launch into a diatribe where he basically says, “I don’t like semi-weighted keys”. But that is no reflection on the quality of this keybed - it is stellar! And the pads are the best there are.
You should just pick one up from Amazon or Sweetwater or somewhere else that makes for easy returns and give it a thorough workout yourself.