I have an F700BT that I'm upgrading to the Z130BT when it gets here tomorrow. My main reasoning was so I could get the new model with the 4volt pre-outs, and A2DP streaming, but also I got a great deal. This Equalizer thing is another benefit I hope.
The reason it is like that on the F900 (and the F700, F90, etc) is that it's only a 3-band EQ, but it has adjustable "Q", which basically changes where each of the 3 bands equalizes and how wide and eqalization it allows (probably just changes how many decibels per octave). Kind of nice for a 3-band eq, but a monstrous pain in the neck to