I have never heard the EM32 before to compare to my NT6pro, but have been doing a lot of comparison shopping to get a backup CIEM having listened through the JH Audio, Westone, Noble Audio, UE, and 1964ears lineups in the last couple of months. My conclusion so far is that at $1250 US, my NT6pro is a steal making it hard to chose a more expensive option that doesn't sound as good. What I am finding is that not only is the NT6pro more extended in both directions, but it is more neutral through the frequency range not messing around with the recording to reveal it as it is. I believe that the 5-way design is what allows it to do so without any significant tuning tricks.
Therefore, the bass is very unique in that it is the hardest hitting that I have heard when the music calls for it, but completely disappears when there is no bass in the music. The 5-way design isolates the frequencies between its 6 drivers so when the frequency is not called for the driver sit silent eliminating the "noise" I seem to hear in a 3-way design giving it - as AJ says - bell like clarity. So the isolated bass drivers are more detailed without the overlap and can hit harder since they have nothing else to do. The isolation also seems to keep the frequencies from stepping on each other as well. In the end,
no demo that I have listened to yet has beat the NT6pro bass IMO - its not too warm, not too cold, it is just right.
The down side is that there is no warm fog over the music to hide its weaknesses so if the song sucks, you will hear it. The warmer models seem to sound their best early in the scaling process, but stop scaling early. So if you are going to stick with an iPhone and MP3s, then any will do and nothing I have heard so far surpasses the value of 1964ears and their $699 US V6 Stage. However, even my $350 X5 or $40 Clip Zip and lossless gives the NT6pro a significant advantage. Believe it or not, I even plugged my NT6pro into the new Schiit stack - Rag/Ygg - at CANJAM last weekend (without blowing it up) and heard it scale even higher than the HD800 IMO given the NT6pro's massive dynamics which matched well with the new stack. So far that is the best I have heard the NT6pro sound. However, it just keeps scaling as I find better sources. That being said, it does make my iPhone sound stellar too.
My advice is that the extra $250 US for the NT6pro is a humongous upgrade from a 3-way, 3 BA setup - but what do I know, I haven't even heard the EM32.