We are using Gainsight in the Customer Success Management Team to manage all our customers and to consolidate the data from all different systems we have to get the full picture of our customers. We are using Salesforce as CRM system, so Gainsight was our final choice because of ease of connecting both.
The support team is just awesome! The response time is pretty fast and most of the cases helpful. We also have a Customer Success Manager helping us in using Gainsight and pointing us to features we have not used yet. In the beginning of our journey along side with Gainsight we had a workshop with our CSM from Gainsight and our whole CSM team. That helped us a lot.
We connect Salesforce and our own Business Process Management software to have usage data. And we use Amazon S3 for other data sources. At the moment we are testing to integrate Jira to also have all support cases in Gainsight and enhance our Health Score with that information (e.g. open cases, critical bugs).
The best scenario would be to use Gainsight when Salesforce is already in place. This will help you to set up things easily, like rules for automation, data transfer or updating customer data in Salesforce through Gainsight. You want to consolidate all customer data you have? Use Gainsight! Gainsight also has a good reporting tool in place, where you also can create and share dashboards.