I currently have ATH-M50s (really enjoy), V-Moda XS (love) and V-Moda M-100 (like for classic rock, but bass can be too much for other genres). My only amp is the Vamp Verza.
So my question is what should I look for in a set of over ear open cans? So far my interest has been piqued by the HD 600s, the Fidelio X1 and to some extent the He-400. Which of these would best complement my music tastes and am I missing any obvious choices?