Heyo, what little things with Reddit and RES have you been missing with the Lemmy UI?
For me it’s been keyboard post/comment navigation (like RES) and keyboard shortcuts. E.g. I can’t post this submission with ctrl + enter as I could on many other input forms.
There is an open ticket or multigroups: https://github.com/LemmyNet/lemmy/issues/818, so you might want to give that a thumbs up to show interest.