High-quality means starting with a verified, clean ROM. You want the file. The checksums (MD5/SHA1) should match known-good dumps. A corrupted base ROM will cause the English patch to fail.
The audio is a standout feature. The soundtrack is catchy and intense. A "High Quality" ROM dump ensures that the sound samples (the drum kicks and synth brass) do not sound muffled or static. Again, accurate emulation is key here to reproduce the SPC700 sound chip correctly.
Downloading a pre-patched ROM from a random website often results in corrupted data, glitched graphics, or poor-quality translations. The most reliable way to ensure a "high quality" experience is to: