In the span of a week the Aroma Audio Thunder has become my reference IEM and the one I grab for long multi-genre listening sessions. I love all music and this IEM is superb on everything.
The bass is full of impact and texture and the mids are nicely layered. The highs while not as airy as some of the EST equipped IEMs I have heard are beautifully done and don't ever tread into harshness. Vocal and instruments have great separation and definition with a wonderful sense of space. Sound stage has good depth and width, though it is slightly smaller than the UM Mest MkII in width.
If you listen to a lot of everything, classical, jazz, electronic, rock, vocal and anything else I believe this is a great choice!