Been too busy to give a short comparison between the h300 and Altone200.
IMO, the mids and highes are very similar with the 2 unit. The biggest difference between the 2 would probably be the bass. The bass on the H300 is BIGGER and STRONGER...
The bigger and stronger can be both a good thing or bad. Because of the stronger bass, it feels like the bass are closer to your ears than the mids and highes. So they kinda push the mids and highes back a bit from your ears. On the other hand, even though the bass on the Altone200 is not as strong, the quality of the bass is actually quite good. Punchy and impactful. Imagine being punched with a bare fist (Altone200) comparing to being punched with a boxing glove (h300).
Due to the less dominating bass, the mids and highes feels more on the same level as the bass on with the Altone200. H300 also have a slightly warmer sound signature than the Altone200.
Overall, they are both very detailed IEMs thanks to the 2 BA drivers; but with some differences in the bass. With the Altone200, I would describe it's signature as an "I" shaped signature, whereas on the other hand for the h300, the signature is more of an "L" shape.
Atm, I'm preferring more to the alight warmer and bassier sound of the h300. However, I also enjoy the slight colder and less bass dominating soud of the Altone200.
With their price at below 150 USD, I've never regretted buying the Altone200. It's definitely one of the favourite IEMs I own atm and I'll highly recommend them to anyone who's looking for a good pair of IEMs with top performance to price ratio.