Objectively, their are no sonic performance improvements between V30 to V60 and all models in between. All exhibit the same nature and headphone power-output. In pure objective measurements using same measurements tools V30 is superior to V40, V50 and V50S/G8X. All models have near identical SNR, THD+N, Dynamic Range, IMD. However V30+ has a headphone output impedance of just 1.1 ohms (lower is better) compared to V40, V50 and V50S/G8X of 1.6 ohms. In comparison Samsung Galaxy S9+ have output impedance as high as 2.66 ohms.
Being a music lover for quite sometime the above measurements have no meaning to me as I believe sound quality is mostly subjective. But then it is me. Subjectively their are variances in sound signature between these models depending on the tuner's like B&O, Meridian and LG itself.
V30 tuned by B&O has natural sound. It will do the hard work and dig the details for you. If not paired with right headphones may sound dry or clinical. The V40, V50, G8X are more forgiving as they tuned by Meridian and sound a little sweeter and are compatible with a broader range of headphones. However they lack the sparkle of V30 at the very top end of audible spectrum. You cannot have best of both worlds. My Vivo NEX S have a bottom end & mid-range which is unparalleled by anything I have come across a smartphone. And that too after hearing the G8X. But where it looses out to G8X by a whisker is in the treble region. The high frequencies are even more prominent on the V30. Subjective preferences vary from person to person and each will give his/her own opinion.
So in the end choose the one your ears love the most, it doesn't matter what others say.
