It's unusual that I'm early to the party, but I'm really enjoying SA6 mk2!
I don't have any other IEMs in this price bracket to directly compare, but so far I'm really impressed with what SA6 mk2 delivers. Tuning-wise it's rather similar to my 64 Audio U6t and A12t, so there is plenty there to like from it's elevated sub-bass with a pleasing amount of mid-bass warmth, and treble that is fairly detailed without any unwelcome peakiness. This is an IEM that will work well with any genre you choose. I've run it through a gamut of Rock, Classical, EDM, Rap, Metal, Ambient and others, so far it's been a real winner, and I'm finding it pretty addictive.
I'll need a bit more time to assess longer-term fit and comfort, which is something I've really come to appreciate in both the universal U6t, and of course the custom-fit A12t, but so far I like it's quasi-custom shell design, and my go-to Final E tips are a good match.
Technically SA6 mk2 cannot keep up with either of the 64's, but then that's what you pay for going up to the higher tiers. For example SA6 mk2 has pretty good soundstage, in fact I'm appreciating the amount of depth it does have, giving it almost a spherical sort of shape; depth is something that can be challenging to get right, and the SA6 mk2 does fairly well. But it's overall a bit smaller, and doesn't extend as far in any direction. This translates into dynamics that don't have quite as much contrast or punch by comparison. I'm also finding SA6 mk2 not quite as refined with treble precision or sharpness, sometimes notes have a slight edginess or "fuzz" to them.
But. These are actually small differences, and the comparison here is a good example of diminishing returns. Depending where your budget lies, you may be happy to pay a premium for an additional 5-20% technical performance improvement. If not, then the SA6 mk2 is a fine IEM that I believe will make a lot of people happy.
