Ask the users. Do they want it? Do they need it? Will they scream at you for not doing something else instead?

Also you must know your position on the market. If you are a big fish already, working on optimalizations most of the time is likely the way to go.

If you are still trying to acquire your userbase, more aggressive development of new, possibly attractive features might be what puts you on the map.

Still, asking the users is very cheap and quick.