Well... Tell us the truth. How does it sound? Do you feel any difference (balanced \ unbalanced) comparing to BTR3? And most important - is it worth it?
I only have a few hours on the BTR5 so far, so this isn't anything set in stone but only an initial observation:
Listening condition (LDAC SQ priority, no EQ and listening to Spotify very high quality)
BTR5 - Apodizing fast roll-off type 1, distortion compensation off, DAC clock divider 1/4, low gain
W5 - ES9218P, single-ended, stock setting
ES100 - 2X current mode on 3.5mm, 1X voltage on 2.5mm, Short Delay Slow Roll-off, 4X sampling
All listening is done on a pair of DQSM Turandot, stock 2.5mm termination with DD-HiFi's 2.5mm-to-3.5mm adapter.
For 3.5mm single-ended:
W5 has the cleanest and most dynamic sound between the three. Despite BTR5 having the same DAC/amp (single ES9218P on the 3.5mm output), the background on the presentation isn't quite as dark and open as that of W3 - it is subtle but noticeable. Between BTR5 and ES100, I can tell BTR5 offers better control where bass note sound deeper and more impactful, which very well could be a result of having more power. Beyond that, the technical difference the two isn't large enough for me to say one if distinctly better than the other, though I can foresee BTR5 might have the upper hand when it comes to more demanding headphones.
For 2.5mm balanced:
2.5mm is where BTR5 shines. Though not a fair comparison since W5 doesn't have balanced output, I can easily tell that I prefer BTR5's 2.5mm over W5's 3.5mm as BTR3's 2.5mm output is just as clean/dark as W5's 3.5mm while offering better separation that probably a balanced output can deliver. Between BTR5 and ES100's balanced output however, it is less clean cut. On one hand, ES100 sounds more neutral while BTR5 has a very fainted sense of warmth. On the other hand, BTR5 offer noticeable better control over ES100. The difference isn't big enough and I think ultimately it will be down to personal taste to say which one a person will prefer.
Last but not least, while EQ doesn't work on BTR5's LDAC, the various filters, distortion compensation as well as clock divider settings do have fairly noticeable impact over the sound, especially on the texture of the music. These have much bigger impact than what on the ES100. I actually still playing around with different setting and haven't settled on one combination yet. It is actually fun to change things around.