SRAM X9 vs X0

[Cappies]

I have a question on the X9 and X0 rear derailleurs:

 

Looking at the specs it seems that the only difference netween the two are the corbon bits and some 30-40g. The rest of the mechanisms looks to be exact. Are the moving parts of a diffirent quality? 

 

I have to choose between the two. R650 vs R1000.

 

(I have x7 triggers)

[GoLefty!!]

The only mechanical difference is the removable pivot pins on the X.0 and the upper pulley wheel on the X.9 is the old eccentric shaft model. X.0 uses conventional pulley wheels

[Little-Ben]

get x9 rd and new x9 shifters together instead of x0 rd, seems like a better option to me