None of those will have more bass than the XB500... If you want more bass than that your best bet is either EQ or the ZO2. No other headphone will give you more bass though. I personally use M-Audio Q40s with the ZO2, and while those have more bass than stock XB500s, XB500+ZO would blow out your brain with bass.
They are supposed to be pretty incredible. The first triple dynamic IEM. The bass is supposedly insane in quality, thanks to a dedicated subwoofer driver. But because the mid and high drivers are seperate from the subwoofer, bass doesn't affect the quality of the mids and highs. The only reason I personally am hesitant to get them is that they are IEMs.