- Realtime chat

- Design that is much less customizable via userscripts/CSS

- More emphasis on users rather than communities (enhancements to user pages, profile pictures that are displayed in comments)

- Garbage native media hosting alongside worse handling of offsite (youtube/imgur) media hosting

- Inline gifs in comments

- Algorithms that emphasize clickbait

- Algorithms that try to guess what you want to see rather than letting you tell it what you want to see

- Suppression of content deemed unsavory by advertisers

- Emphasis on mobile design over desktop design

- Backward incompatible changes