Don't try to patronize me. You don't realize that I'm 3 or 4 times older than you.

Unless you are into powerlifting, lighter equipment are usually preferred as they cause left stress on the body. In this case, less fatigue in the fingers. But, indeed, if you prefer a heavier equipment, it's a matter of preference.
Now, the weight isn't the only factor. Stability is a much important factor.
If I would like to talk about my preferences, I would have said that I don't like the touch feeling nor the taint of some colors of the RS3M but those are indeed preferences and not facts.
Maybe you don't realize that you are trying to rationalize your preference for an objectively worse cube.
If the people at Moyu had thought the RS3M has flagship qualities do you really think they would have fix its price at less than 10 bucks?
Seriously, there is no possible debate if all you have to say is "everything is a matter of preference".