What do you look for when choosing a customer success software?

First-time software buyer here! I am starting my research on customer success platforms and want to talk to some experienced members of G2's community. What software features are the most important to you when selecting a new software solution to add to your stack? I've read a ton of reviews of products on G2 and feel pretty good about Gainsight CS and ChurnZero. Does anyone have experience with these tools? My working research is below!

Gainsight Customer Success: Gainsight Customer Success is a comprehensive customer success platform designed to help businesses drive customer retention and expansion. It offers tools for health scoring, workflow automation, and customer journey analytics, enabling teams to proactively manage customer relationships. Gainsight CS is known for its robust feature set, which may require a dedicated team for implementation and management. While it offers extensive customization, new users might experience a learning curve. ​

ChurnZero: ChurnZero is a real-time customer success platform focused on reducing customer churn and increasing lifetime value. The platform offers flexibility and customization, allowing businesses to tailor it to their needs. Its focus on real-time data helps teams act promptly to improve customer experiences. ChurnZero integrates with various CRM and communication tools, facilitating a cohesive approach to customer management.

I'm leaning towards ChurnZero, but I also don't want to rush into making a decision. Let me know what you think and any advice you have for a first-time software buyer. Thanks in advance!