Oh, that would be very interesting :D
I ordered the SM3 one day before Earsonics announced the SM64...I choose to jump in at the deep end and changed my order to the SM64, hoping for a sound, similar to the SM3.
The iBasso sure helped me to amp up the SM64 and now I can listen to them with proper volume :P I don't think it changed much SQ-wise.
I also started to use the eq of my Cowon (am I a bad person for using it?). I set the BBE to 5 and now the sound is way more lively!
I think SQ-wise the SM64 are preety damn awesome! The unique soundstage, top notch clarity and seperation, tight, textured and controlled bass, really nice mids and crystal clear highs.
But the sound signature can be a bit exhausting at first (says me, coming from the TF10!). The highs can go pretty high (if necessary) and the overall really neutral sound signature was a bit of a shock to me to be honest...
But I think the more neutral the sound signature is, the better you can EQ it as you like. This small change in the equalizer made me love the SM64 even more!
Now they really have everything I want from an IEM :)
I can't wait for the first "proper" reviews :P