I already had an old unifi (about 5 years old). It was only capable of 2.4ghz and occasionally made faxes.
i've been using the new nano for 2 weeks now and i'm very happy with it. it's very quick to set up via the app. the most important things can also be controlled via the app. i only use 5ghz now. the speed is top. i also think mu-mimo will be the future, so i can only recommend it.