If I have items filtered by search terms, like "avocado" or "+NewUI @office", and I click the + button to add a new task, it would be nice if that new task was pre-populated with the search terms.
I like to be able to look at all the tasks in a project ("+NewUI"), and think if there are other things that need to be done. Using the + button to add a new task that is by default in that project would save me a few keystrokes on one new task and maybe a lot of keystrokes if I add a lot of tasks.
I have this happen for contexts too, but less often. Usually with shopping lists ("I have 'toothpaste @drugstore' and 'mouthwash @drugstore', oh yeah I also need 'dental floss @drugstore'").