It's easy to use, very good for tracking clients from start up all through lifecycle of their project or projects (if you offer more than 1.) Great tool! I like it because its simple yet has lots of features that help with managing my client relationships in one place; this is great if they have multiple people at your organization working together across different departments as well.
Nothing really - I've been able to track everything needed via an email exchange between myself and them since we started using digital horizon many years ago now.