FA is a full fledged Accounting Software with ERP extensions built in. Financial, Logistics, Manufacturing and simple document management along with a simple CRM are in it. If there is anything more you need in your ERP, you can extend FA with your custom extensions. It supports themes and multiple platforms for servers.
The best way would be for the end user or their consultant to try FA out firsthand for suitability.
Key metrics besides cost (free for code but need to pay for implementation and maintenance like all other ERP) would be:
1. time to migrate data in and out,
2. extend functionality and
3. no vendor lock-in for code and support and
4. no Damocles Sword of unknown legal liabilities and licencing issues.