I’m located in Ireland. I have 5 apps in the Appstore my biggest app has well over 150 screens 8,000 users and 40+ databases which many are many to many. Down load and test the speed if you wish.
I wrote a post here might give you confidence.
Now I develop for my clients completely in Adalo, having used Expo / React Native before, and before that native code.
There are some speed issues when you try to run lots of functions in your lists, or try show everything at once etc… But any app would slow down under these type of conditions. I laid out some points that I stuck to when developing this app in particular.
For me I feel the app works snappy. And I can say first hand the speed improvements by Adalo over the last year have been significant, and I know it’s only going to get better. The reliability of the Apps uptime are also v good! I have clients that use another of my Adalo App for 1000 daily users to make gym bookings and had no issues at all for multiple classes and groups.
Enjoy