Compare the actual workflow
Test the same representative journey in each option. Include an exception, such as a customer with two accounts or a document that must be visible to only one contact.
Look beyond the feature list
Check permissions, exports, API access, accessibility and the ability to leave the platform. A listed integration may cover only part of the process you need.
Calculate continuing responsibility
Hosted software can reduce some operating work but still needs configuration and governance. Custom software gives more control while adding responsibility for maintenance, security and deployment.
Use a reversible decision
Begin with the narrowest approach that can meet the important requirements. Record the conditions that would justify changing it later, such as a missing integration or an unacceptable operating cost.