My thoughts:
- You don't need to use SMS/text notifications. Even in the US (not sure if they work in the UK), you're limited to 10 a day. There are a variety of notification services you can use instead. Pushover is popular. Since you already have ST, you might be interested in this (which I'm using) instead; Route Hubitat Notifications to SmartThings (App and Driver)
Note that in many (all?) apps, you have to select notification devices as "speech synthesis" or similar--should change when Hubitat gets native support, coming in the app; this is just a workaround these other solutions use.
- I agree the dashboard could use some professional design help in the UI, but you can customize it a bit yourself. If you're OK with cloud-only access, there are also non-Hubitat Dashboard alternatives like SharpTools (native integration), or you can use the community-created Other Hub app and DTHs to "sync" your Hubitat devices with ST (might be useful during your migration anyway) and then use the ST mobile app, ActionTiles (if you have that), or whatever you want as an alternative interface. The Hubitat admin UI also works for device control, though it was not intended for that purpose and isn't very pretty, though it works in a pinch.
- There is no native Ring integration. I think it's on their wishlist. I'm never sure what people want with camera integrations, though for the doorbell I'm assuming you want motion and presses. You can work around this with IFTTT, supported by both Hubitat and Ring. (Create a virtual device or two in Hubitat and have IFTTT control it/them as appropriate--ask for more help here if you're interested.) If you have an Echo/Alexa device, you can also do something similar with an Alexa Routine.
As you note, the app is coming. It should provide easier access to dashboards and notifications, among other things. You probably won't get another way to control devices, however--just access from the app to dashboards, which staff have indicated is the intent for device control. I don't really miss having an app myself since everything I could do with it I can already do.
