It’s nice and unintrusive, switching devices works pretty fast, it’s great for typing, but lacking a bit on shortcut-side, partially due to OS X and iOS sharing some system shortcuts that can’t be captured on OS X, but partialy because of the app. My biggest issue is that hitting escape disconnects from iOS devices. There are iOS apps using escape as keyboard shortcut so it’s quite frustrating when you want to use those and you disconnect instead. Especially since you can use escape when connected to Apple TV. Since cmd+tab does the disconnect automatically (I’m guessing stuff like that and Spotlight can’t be captured, but it would be a killer feature if it was doable) and there is also a custimizable keyboard shortcut to toggle between dektop and device, there is really no need for escape to do it too. Media keys no longer seem to work (tried from multiple Macs with 10.11 to multiple iOS 9.3 devices).
Overall it’s a decent keyboard replacement and definitely worth its price, but it still has a lot of untapped potential.