Well, I couldn't resist the temptation anymore and finally bought a pair of XBA-N3AP. Initial impressions are very good, even if these aren't necessarily perfect IEMs. Here are some observations:
—as the N3AP are tuned to be very smooth, they play at the verge of sounding unexciting. Previous Sony high-end IEMs had a little bit more "edge" to them, which contributed to that characteristic Sony Sound Signature.
—the aural impression (especially the bass) depends very much on the right choice of eartips. In this regard the N3AP aren't forgiving at all! I found the Triple-Comfort eartips bordering on a flat and lifeless presentation. The same with the silicone foam eartips of previous Sony IEMs. If you want a solid bass fundament, then the standard silicone earbuds seem to be the best option. In my case, the green M-size tips showed most of the "musical", extended bassline that is such a strong point with both the XBA-A3 and Z5. Already changing to the smaller S-size buds resulted in a less articulate bass that peaks in a narrower frequency range and thus sounds more "boom-boom", just like I remember it from the A2. It was surprising to hear such difference just by varying the eartip size. Occasionally, the bass sounds a bit "processed" as if the dynamic drivers are tuned to their absolute maximum and don't have many reserves. It's a very nice and smooth bass, though.
—the M-size tips sound best for me with most extended bass and treble, but very annoyingly, the skin at the tragus gets pinched between eartips and the black housing whenever you insert the earphones. That is painful and very uncomfortable. I wonder if other head-fiers experienced this as well..?
—nice looking semi-transparent cable is more tangly because of its circular section. Unfortunately, Sony omitted the pill-shaped section of their previous cables.
While that all sounds probably pretty critical, it is rather meant to give you a clearer sense of the strengths and weaknesses of the N3AP. Overall these are definitely keepers, capable of replacing my beloved XBA-A3. More impressions of their sound coming soon...