The most helpful feature of this software has been its ease in integrating it into our Salesforce CRM tool which makes everything so much easier for us as we are able make calls from within one screen instead going back out onto another program if needed! We cannot really think about anything specific right now but I do know they offer free trials/samples before purchasing their product - something worth considering since many other similar products may not provide such an option (though there's always trial versions available).
If someone wants great customer communication without having too complicated or expensive options then definitely go ahead & try them first because all reviews say how good these guys were at what thhey sell!! Customer Service was very responsive when needing assistance getting things set up correctly etc..