What exactly are you asking? Your statement leaves a rather wide point of topic to be discussed. Those peaks and breakups you're talking about can usually be controlled, at least to a certain extent, by proper dampening. At least that's how I've always understood it when splashy treble is a problem. Take away the extra energy cause by the resonance and the upper sig sounds cleaner.
Well I didn't want to make a blanket statement like "the higher the break up point the better!" The thing is, as I understand it, the break up point doesn't just mean excess treble energy that can be dealt with by dampening etc. It means that at certain frequencies the driver will begin producing other unwanted frequencies as parts of the driver begin moving out of sync with other parts. ie: this is a kind of distortion, and why electrostatics were designed in the first place.
Since you can't selectively damp different frequencies at different times (you cannot deal with distortion by damping) it points at how material selection for the driver is a design choice.
Only saying this because I'll be interested to see again if Sony can do something interesting with their LCP driver which didn't seem all that great in the Z1000.