The safest way to ensure what the vendor has now covers your needs is to talk to existing customers. This should be a "must-do" item on your pre-purchase checklist.
Identify the customer references that most closely match your situation and spend some time investigating their degree of satisfaction with both the product and the vendor’s services. Include both new and longer term customers to gain a fuller perspective. Create a reference check worksheet to record your findings; this can also be emailed to any reference that prefers to provide a written response. In larger scale projects and if welcomed by the reference site, a visit to that site will provide even greater insight into the benefits of the solution.