So I just changed my phone and the new App came pre-installed, so decided to give it a try before installing ST Classic.
So far not that bad, I do have several devices with custom device handlers, but most are switches/bulbs so I jsut created virtual devices and link these to the actual device through Smart Lightning, so a hassle but have all switches lights working.
I also changed a couple of Sylvania RGBW Bulbs I had back to default device handlers and these are recognized and work now (with added benefit that they run as local devices now), I also changed to the native Color Coordinator SmartApp and its working just fine.
I also created some virtual devices that pair to my Fan Speeds and light so that also working
Harmony App and activities are working
That only leaves me with a couple of custom devices that are not working on the App (Nest, RBoy Custom Lock DH). I will try to change Schlage lock back to native DH later
Almost all my SmartApps are there and work OK, CoRE and Action Tiles continue to work and can be accessed through new App. The only exception is Life360, I don’t see it in my list of SmartApps and presence is not updating in the new App (and get the Can’t connect in the presence cards)
At this point I think I’m going to stick with the New App and just find workarounds to the things not working.