i would say. iMO, that the VSD!s are a great mid fi all around iem, very pleasant sounding and energetic. However the Bassos have much more dramatic impact attack and wider soundstage that is almost "over the edge" but works well for electronic, esp. psytrance. the Tenores are a polite, refined more accurate iem that reminds me of my xba3s, and sounds more like studio refined sound than the live sound of the Bassos. as Mark Twain said, "you pays your money and you take your choice"
all 3 need extensive burn in, in fact, i did not enjoy the vsd1s until about 100 hours of burn in when they changed and become less shrill and the bass increased and became more
impactful and less fuzzy. so burn baby burn!