Major downside it only has 4GB of internal memory. for any android version 4.1 and above, the internal memory should be 8GB minimum, because we can’t transfer the app to the external memory. With only 4GB of internal memory with Android version 4.1 and above, you’ll have a problem of full memory very soon.2GB usable(from 4GB internal) for installed apps and data stored by apps, which is pretty low.
specification wise, samsung galaxy s4 mini(dual sim) wins hands down.