The UI is very simple to use. It has all you need at your fingertips without having to go through pages upon pages just to find what I am looking for or learning how something works! Not much that's bad about it though - maybe some minor quirks here an there but nothing major enough where i'd say "this needs improvement". This software was great when we were using Mailchimp because they had integrations with other 3rd party platforms like Facebook Ads Manager so this helped us get our campaigns up faster than ever before (we used mail chump).