I think it, as always comes down to what you listen to and how you use them. Technically, the increased perception of detail is better on the FH3 for me as I tend to listen to more vocal focused music and its more forward presentation suits that compared to the more recessed midrange on the N3. This holds true for the treble as well where there is more emphasis with the FH3 - neither is in any way overly sibilant or fatiguing.
Bass is where both of these excel but in different ways and I chalk it up to how my brain interprets the overall frequency response of each IEM as a whole. The graphs may not necessarily bear this out, and this is why I don’t I don’t base my choices off of them, but the N3 has great overall tone with good extension, quantity, and note definition, but it is always present and my attention is ultimately drawn more towards the left side of the FR curve. This is not the case with the FH3 as the more forward mids stay up front until it is time for the bass to announce itself which it can do with great speed, tone, and dynamics and this is what accounts for the fun factor I alluded to in my previous post.
Fit, ease of use, and accessories is where the FH3 pulls ahead with respect to user experience and value. The N3 is easy to put in your ear, but that makes it easy as well to come out as most of the weight is centered at the furthest point from your ear where the cable attaches and pulls down. The ear tip is the only thing holding it in. The cable is most likely light for this reason, but it is extremely thin and tangles easily. I’ve upgraded my cable and recommend it, but it is one more additional cost. The FH3, on the other hand, is extremely comfortable for my ears and the cable is of great quality and helps it stay put.
If money is an issue, the N3 is not the best choice here at double the price not including a possible cable upgrade. I’m a huge Sony fan and realize things like collectibility and residual value can come into play, especially with iems that were test beds for technology that eventually went into the Z1R, but you should not be worrying too much about missing out on much, if anything. Good luck.