I like that it has all my clients in one place so i can easily see what they are doing without having multiple programs open at once! It's easy enough if you know how but not very intuitive otherwise which makes training employees difficult as well sometimes since there isn't much documentation online or even an FAQ section about some things (like creating campaigns).
There aren’t many other options out their either unless your client already uses HubSpot/Salesforce etc., however we do use SalesForce now because our accounting department wants us integrated into this system instead of Excel spreadsheets anymore - great idea though!! We have been able to keep track more efficiently than before using zignel enterprise software along side sales force cloud CRM integration!