Metadata is stored in discrete fields
When I mentioned previously that the fields would be appropriately parsed by Smart Add, this is only possible because Remember the Milk provides discrete metadata fields about your tasks.
Good design would dictate that you don’t store disparate data in the same field, but this is the strategery that Todoist takes with labels, URL’s and the task description. Only due date is split to a separate field. In fact, Todoist doesn’t offer a location field or URL field.
RSS is dead. Long live RSS.
RSS Feeds are quite handy in a lot of areas and having one for your tasks, as Remember the Milk provides, while in no way necessary, is quite a nice feature to give another opportunity to review your task list while you might be perusing Feedly (or your reader of choice). One of the bright spots of using a really old tool, I suppose.
Todoist doesn’t provide RSS feeds.
Search is persistent and better
If I search in Remember the Milk, the search results don’t go away until I close them or I refresh the page.
In Todoist, I’d have to remember what my search terms (more unlikely than not) or save the search as a filter in order to see it again quickly.
Searching completed tasks is also far simpler in Remember the Milk.