The ASG-2s weren't designed really as detail monsters... They are designed more to be a warm, inviting sound signature that is entirely non-fatiguing. This sort of signature does have its drawbacks, but very favorable for its inoffensive sound. So don't expect the ASG-2 to really produce the high detailing that you'd expect from an IEM that was designed for that :p As for dynamics not being able to be as accurate as a BA, HiFiMan RE272; nuf' said.
I know. Which is why I'm on the search for detail monsters! The ASG-1.3s (and eventually ASG-2s) filled the hole left by my HJE900s. I might get RE-400s until I can get a high end set of UIEMs or CIEMs to fill that gap of neutral detail oriented IEMs.
I've heard tales of the great accuracy of the RE272. However, I've also heard that the Heir Tzar 350s are unrivaled in their neutrality and accuracy (even compared to the ER4)... So... I'm going to have an interesting journey. After I save up some money of course.
Someone just made a big post about how the Tzar 350 is not neutral and how that term is being thrown around in the Heir thread. The 4.Ai is said to neutral, it's no where near...