After the excellent CX98, I'd got the CX98S to see how far boarseman can improve their products further. Although CX98S might seem to be slightly better in terms of mids and vocals, the difference is quite minor, considering the fact that you can get two CX98 for the price of a single CX98S. In my honest opinion, if you're planning to get the CX98 or the CX98S, you should go for the CX98, as their price/performance ratio just makes more sense. But, if you want better-looking and better-built earphones, and even a better package and more ear tips, you should go for the CX98S.
Just like the CX98, these earphones are for audiophiles, not for bassheads.
Surely you'll find the tips that most suit you. I also had no trouble with finding the perfect tips for myself.
Lows / Bass
These earphones aren't bass-heavy per se, but they are very bass-capable, in a sense that the bass is extremely precise. If you want a more bassy sound, just turn on the bass booster on your device and enjoy a distortion-free sound. As compared to CX98, the bass seems to be slightly less emphasized, even if it is actually more responsive as can be seen by the frequency response curve. Still, in reality, the mids seem to be more prominent and the bass seem to take the back seat.
Mids / Vocals
The mids are clear and very detailed. Some of the best mids I've heard. Slightly more emphasized and detailed than on CX98.
Highs / Treble
The treble is vivid and highly detailed. Could be even harsh on the ears sometimes, but it's extremely detailed. Slightly more balanced than on CX98.