We see a 50% matching rate, there is room for improvements there. We miss the batch endpoint we had in the v2. Some data from the Enrich API have too many fake positives, especially age, employment, and education. We miss a well-documented list of available profiles networks. Outdated data is expected in this kind of APIs but a timestamp about when each data point was updated is desirable to manage when to discard them.
A rate limit of 600 queries per min is very low if you are batch processing profiles. Review collected by and hosted on G2.com.