I think it is great that you can get your emails to go out at different times of day. You also have options for how frequently they are sent. It was easy to set up and start using with my current email provider (Gmail). Nothing specifically - just like any other tool we use in our business. If you're looking for something specific then look elsewhere! There really isn't anything wrong with this service. The platform works well and is quite flexible if you need more control over certain aspects of sending. We've used it primarily as an additional option for bulk emailing but sometimes we do send time-sensitive messages too. They are very professional and friendly people to work with! The team at Katzion has been able to build a great platform for us. They have always been helpful during any issue we've had. It's a great experience working with them. I can't think of anything I dislike about their service. Their website is easy to navigate and find what you need in a timely manner. We use their API in order to integrate our application into their site.