They are more neutral sided to me with a slight emphasis in sounding almost balanced, very rich and clear, not too warm, nor too bright. The Andromeda's has more weighted bass and slightly sharper highs (maybe, due to the BA armatures). Probably, that's where some owners are noticing brighter or shrilled highs. The Oxygen don't pose that threat, since they tend to stop short of ever sounding harsh or sibilant with most genres when I listened to them for 2-3 hours at a time. One dynamic driver type earphone I learned to appreciate were the SONY MH755. But, listening to both, the MH755 bass started to somewhat weigh more in bass and the midrange and treble seemed to lack extension when compared to the Oxygen, which carries a more neutral-like and natural sound signature with good texture and excellent clear details. Now, back at my friends shop, I also wanted to audition the ibasso IT01, and the KPE, but they were not out for display at that time. Hopefully, in the future they'll have one on display to compare.
Lastly, this was all in the name of fun, since I won't be buying more expensive "out-of-my-price-range" earphones anytime soon! ...At least, not close to the Oxygen in price.