What do you like best?
Easy to operate, fast. Has build in preview for basic files, so no need to open in editor (payed version).
Zero inbox pushes you to clean the inbox and handle/solve/clear all the emails.
I especially prefer the possibility to have add-ons on the sidebar, as this saves another applications or browser windows from running
What do you dislike?
Search functionality could be better. There is no possibility to filer what and where to search, it always searches in the whole email account. Some nice filtering after search would be also great (I'm missing the great search that Thunderbird had)
Recommendations to others considering the product
For sure, need to give it a try.
At first, can be little different workflow then you are used to, but has great features/possibilities.
What business problems are you solving with the product? What benefits have you realized?
All email communication. Tasks management. Calendar.