Ok guys....
I will correct my last post about the weight and why I can NOT reduce drastically the MS weight.
Here the points:
1) we use the best Fatar Synthesizer keyboard TP/8SK 76 keys weighted and ONLY this keyboard part is about 12Kg. In our MS production we will never use the cheap plastic and short 61 keys models that are about 5Kg. We are not interested to produce Home keyboards but only professional workstation models.
2) With the 76 keys weighted model we MUST use a metal case, because the keyboard is to much lenght and deep, NEED a stable case structure OR when you pickup the MS in one side, the cover and bottom case are moving like a sandwich.
3)12 PCB boards, Mainboard, ATX powersupply, HD IDE 3.5, DVD drive, Display have one weight that we can NOT cut or reduce. Buy there one standard ATX OC case, install the all hardware and you have a basic weight too that you can NOT reduce.
4) FCC and CE approval: Inside the MS we have one standard ATX PC with the standard ATX power supply where the ALL boards MUST be fitted in a Metal Case with the same Ground. CPU over 800/1000 Mhz clock have a lot of interference, NEED a metal case or we never can have the FCC/CE approval. So..untill we will use a standard PC CPU we never can make the MS under a plastic case.

These are the BASIC reason why we can NOT make the MS less weight and that will never be a Home keyboard.
I think now you have understand our position and why I will not listen about this arguments because I don't have any chance to design it again under plastic parts.
Is a compromise..if you like the power you need change the case too.
This is like a car, if you have a 100Hp engine this need a 15 Inches wheels, but if you have a 400Hp engine you CANT use the 15 inches wheels you need to have the 19/20 inches wheels too, it mean to change the car case too, right? Can then have the same weight with the new bigger parts?
Is a compromise, try to understand me too.