Well then you simply don't understand what makes construction of a mechanical device robust or not. I guess you don't own power tools.Well, devices that take part in recreating sound, and are sensitive to vibration affecting that sound, can have a benefits of weighing more. I think that relies on the design and actual materials more so though, IMHO. I got a new turntable recently that's very light yet I find it built to the highest possible degree and sounds superb. Then you look at Mike's new Saskia table which is ungodly heavy and it is also built extremely well and sounds superb. I really see no relation to actual weight making any difference whatsoever, especially for a RCM.
On a happy note, maybe this will be the one piece of stereo equipment my 8 year old daughter can move around.