Most of the changes have already been introduced in Release Candidate version, i.e. 3.5.4.RC.1, although some new tweaks and bug fixes have been made as well.

1. (+) There is a new attribute (Page Heading) and the setting (Page heading override) - within categories and products - which both allow to give better control overheading on product and category pages.
2. (+) We added "Show on google map link" into the map markers.
3. (+) There is a new version of Filters Module (mod_djc2filters). It introduces new type of filter (Checkbox OR) that applies to checkbox fields and becomes the alternative for already existing Checkbox filter.
4. (!) SEF router has been modified. It is now more strict when it comes to recognizing category/product ID parameters and is more likely to throw 404 errors when necessary.
5. (!) In some cases, upon saving a product and changing its group of extra fields, the values of old attributes were not deleted. It has been fixed now.
6. (!) New version of Producers Module (mod_djc2producers). It fixes the conflicts between two module instances on the same page.
7. (!) New version of Finder plugin (plg_finder_djcatalog2). It fixes the problem with indexing child products.
8. (!) New version of Categories Module. New classes have been added to sub-category <ul> elements.
9. (!) Problems with contact and product submission forms ("0-Invalid address bug") have been fixed. (Joomla 3.5+).
10. (!) Problems with invalid database COLLATION when using alphabetical filter (A-Z) have been fixed (Joomla 3.5+).
11. (!) PHP 7 compatibility. In some specific cases, the list of extra fields values were not listed in the product form. It has been fixed.