So I've been enjoying the XB900 all day today. If they are the same as XB800 then there is something wrong with my XB800. The XB900 sounds like the X10. It's awesome! I'm gonna get another pair of XB800 just to see if there is something wrong with my XB800 because the XB900 is 10x better.
here are some pictures of the two.
XB900 on the Left, XB800 on the Right. Aside from the aesthetics of the cups, MDR-XB800 also is taller than the XB900.