My two main playing basses are a 535 and a BN5. In the continuum of basses between vintage and modern, a 535 is pretty far to the modern end, while a BN5 is somewhat toward the vintage end. This is mainly a function of the pickups and electronics.
The 535 has a clarity and pureness of tone that dominates the sound to me. Keep in mind my bass is solid myrtle burl and wenge/wenge, so it is not a typical 535. I believe most 535s have a little bit more grind/snarl/compression, whatever you want to call it, but the Barts and the preamp are certainly designed to give a clear, bright, snappy, kind of solid state sounding tone. The wood changes the subtleties of that tone. I find that the EQ changes the fundamental character of the bass, but also I find that you can't go too far on the boost side without things getting a little squirrely. Cutting EQ is effective (and almost a must for treble with brand new strings), but I mainly boost only the bass EQ a little to get more bottom as needed.
The BN5 has what I would describe as a warm, rounded tone. Not quite fuzz but a bit of color. The preamp comes across as very clean in terms of noise and transparency of the pickup sound, but there is a warmth to the sound coming out of the bass that suggests a warm tube amp. Compared to a typical JJ configuration (Fender or a number of derivatives), the bass is a bit polite, not quite as rough or snappy, but with EQ you can dial quite a bit more personality into the sound. The preamp beats the 535 preamp in spades. It takes a bit to come to grips with the Vol-Vol configuration, but the quality of tones and usability of the EQ is remarkable. It is truly a player's bass in terms of having 3-band active EQ and passive tone knob, the ability to switch to humbucker mode (which I would only do if RF noise were a problem in a room), and the ability to toggle active/passive, where passive works even with dead batteries. (The 535 is no go without batteries.)
Other key considerations include 1) 35" scale for the 535 vs. 34.5" for the BN5, 2) neck contour, with both narrower than most 5-strings at the nut, neither particularly thin or chunky in terms of depth, but with the 535 a little flatter and asymmetric compared to the BN5 (a little rounder), 3) the way the basses hang is quite different, with the 535 the most comfortable fitting bass I've played (great back contour to fit around your torso) and the BN5 designed to minimize the reach to the nut (neck built more into the body, 4) finishes - I think most 535s look better than most BN5s, but either can be had with exquisite tops, and finally 5) price - you can get into a basic BN5 cheaper than a basic 535, but the options on a BN5 drive the price as high or higher.
Hope this is all helpful info. You can't go wrong with either. On the other hand, if I were in a metal or hard rock band, I don't think either of these would be at the top of my list. These cover just about all the other bases very well. Fit and finish on both are spectacular, and both are easy to set up very well. My 535 feels a little more handmade than my BN5 (probably due to the wenge and the asymmetric neck) and is slightly better intonated from top to bottom, as close to flawless as a bass can be. My BN5 feels perfect up and down the neck and is similar to a Sadowsky feel in that the design is essentially "perfected jazz bass."