I don't use gedit, but in general I like look and feel of GNOME 3 applications:
* Emphasis on undo instead of confirmation dialogs. Though, some applications got implementation completely wrong. Contacts, I am looking at you. It delays deleting a contact instead of offering a real undo, which means that if you exit early no action is performed at all.
* Different colors for constructive / destructive actions used consistently across applications.
* Keyboard shortcuts window. Though, I don't understand why most applications insist on making it modal, which essentially prohibits looking at shortcuts and trying them out at the same time.
* Headers bars. I prefer those over traditional menu bars, especially if number of different actions to perform is limited. Though, portability suffers as making it work in environments without client side decorations requires some custom code. Thus, if developer didn't take this into account it probably doesn't work.
* In-app notifications (used for example for example for undo I have already mentioned). Though, AFAIK this doesn't seem to be builtin part of GTK yet and require a little bit more custom code than other widgets.
* Empty placeholders! (Though, they might have been there already?)
* Emphasis on undo instead of confirmation dialogs. Though, some applications got implementation completely wrong. Contacts, I am looking at you. It delays deleting a contact instead of offering a real undo, which means that if you exit early no action is performed at all.
* Different colors for constructive / destructive actions used consistently across applications.
* Keyboard shortcuts window. Though, I don't understand why most applications insist on making it modal, which essentially prohibits looking at shortcuts and trying them out at the same time.
* Headers bars. I prefer those over traditional menu bars, especially if number of different actions to perform is limited. Though, portability suffers as making it work in environments without client side decorations requires some custom code. Thus, if developer didn't take this into account it probably doesn't work.
* In-app notifications (used for example for example for undo I have already mentioned). Though, AFAIK this doesn't seem to be builtin part of GTK yet and require a little bit more custom code than other widgets.
* Empty placeholders! (Though, they might have been there already?)