The A100PCI is well designed to suit the world wide pstn impedance, and have very good quality, the components is fully surface mount now. and also we are patching the driver to support the polarity reverse.
the oem x100p is a cheap products, not suggest used in critical environment or product.
We just released the new design A100P, feature is :
1. Real global pstn impedance, do not have echo issue.
2. Full surface mount components, high quality,
3. No cid bug,
4. Provide low profile pci bracket version, can be installed in small size pc.
5. 1 year warranty