UI design is extremely faulty
The testing process is very tedious to set up and makes it easy to make mistakes
They constantly make updates that do little to effect the bigger issues and are not completely upgraded
They don't provide scheduling options like "send-time optimization" as an option for A/B testing
Backend team solutions usually provides workarounds on how to function on their ESP but hardly find solutions
Segmentation - is VERY clunky and not efficient whatsoever. Some options do not work properly, especially their location function.
Dynamic content - does not dynamically change content the way you structure it. Extremely faulty and not reliable.
If you pick out a bug in the system it could take weeks or months to get the issue resolved
Creating web page - most icons do not work or function properly
Overall, the ESP has many many challenges. I've personally worked with several different types of ESPs and this so far is the worse one yet. The only way to succeed with this ESP is to constantly figure out workarounds. This makes the user experience VERY challenging to do even the most minimalistic tasks and makes it difficult to execute. Whenever there is an update I am always cautious. Usually, it doesn't work properly or it comes up an array of other issues. I have very little faith in this ESP because it has been so painfully disappointing.