I bought an upgrade from ENX7 to EN20, was enormously annoyed and downgraded to ENX9 after 4 weeks. These are my reasons, which I have also communicated to customer service:
Show/hide selected References: Function deleted: To identify difference in authors first and middle names (APA style), which influence appearance of citations in text, critical references have to be grouped. This is done by show selected references. There is no other simple way
Go to next reference (edit): Function deleted: For systematic corrections without leaving edit mode, go to next reference is necessary. This function was able to land in exact the same field in the following reference. Very time economical
Bibliographic output field: Moved and only visible after double click on reference, activating panel: Alternative way: 4-fold click amount. It is sometime necessary to know how the default formatting of the reference is chosen, when full reference style is copied (to a powerpoint presentation etc.), where no formatting function is available.
Clear Search: New function in EN20. Works only when search provided hits: Why is this button not permanent active to clear the search panel independently of search results?
Appearance: ENX9 → friendly colours, EN20 → dark mode, heavy metal appearance
Reference rows distances: In EN20 to wide: Only half of the references can be seen in comparison to former versions
Display fonts: Not any more selectable. Instead, selection between default and a too small font size: For individual vision not sensitive enough (too big or too small, but not convenient)
Preferences: X7 and EN20 use the same ini-file: A parallel use of both programmes is not possible, as both programmes open the same selected open library my default. As the use different database structure, error messages occur
Additional Reference panel: nice function in EN20, but useless, unless Windows does not allow to horizontally or vertically tile: badly thought-out
Search results: In EN20 not any more displayed in group panel: As a consequence, search has to be repeated several times, when scrolling through results->Very time consuming
Groups panel: EN20: A lot of unnecessary information lines reduce the view on groups: Field information lines should be selectable in preferences
Import Icon: Icon deleted. Alternative way: Threefold click amount: Several clicks are required to import a file: file → Import → File
Show file Icon: Icon deleted + Keyboard shortcut deleted. Alternative way: 4-fold click amount
File attachment (right click): Moved to summary: 4-fold click amount to link reference with pdf