I drive BD-Design speakers with my Leben CS300Xs and they play very well. Mine are not the usual horn-loaded speakers that Bert Doppenberg at BD Design sells, but a variation of an open baffle design he referred to as Quasar II. His horns are very efficient and the bass is sub-amped so the Leben has more than enough power to get real-world listening levels. The driver doing the mid and high end in mine is the Lowther PM5A (extremely powerful magnet) with solid silver voice coils (and no Hi-Ferric for those who know). These speakers sound very good, better to me than most of those mentioned so far on this site (I've not heard the Zu). I play mostly vinyl and through the excellent Leben phono stage.
I have two pairs of headphones, old (and not top of the line) Bayerdynamics and Sennheiser's. I use an admittedly cheap adapter between the small plug end on these headphones and the Leben, so perhaps that is the reason why I prefer to listen over speakers, but if any of you have heard BD-Design speakers and know of better sounding headphones (and cables) then please let me know. Your expertise is greatly appreciated.