We have an AltaGrade customer with Drupal 7 with lot's of different features that all can be easily replicated on Backdrop. And initial pitching Backdrop to this customer went quite good and we've got their positive feedback. The only obstacle not to move ahead with the migration is the fact that the photo gallery on the website is based on Node Gallery module. Unfortunately, not only the https://backdropcms.org/modules?s=gallery page doesn't list the module (so it's not been ported), but also gives quite limited options of alternatives.
So I wonder what path the experienced Backdrop users would recommend to our use case? Does any good photo gallery solution exist for Backdrop? If there is none yet, then AltaGrade team would get one of the D7 modules ported, however before starting to spend time and to put efforts into porting anything, maybe we should find the best candidate. For example, some Drupal 7 users prefer Photos over Node Gallery. Maybe there are some other even better candidate alternatives for porting to Backdrop.