I swapped from stats to iStats a few years ago. I've found stats to be easier to customize and the UI is more uniform. That said, it doesn't have the weather widget, so I've kept iStats around solely for its weather functionality.
System Settings > Control Center > Weather
I am still on 15.1.1 too as I have been waiting for a 15.2.1 for bug fixes, but they released 15.3 instead.
thanks. now i'm wondering why it hasn't been pestering me to upgrade. i just went and looked, and now it sees the upgrade possible. i must have told it later and promptly forgot about it