Best Smoke Detector to use with SmartThings - Nest or other?

Do you have a link to the best way to integrate … I have seen online NST Manager

([RELEASE] NST Manager v5.0)

and this

([RELEASE] Resilient My Next Manager & My Next Devices for your Nest® products with native UI (for faster rendering on Android/iOS) & all ST standard capabilities + high refresh rates + No complicated developer account setup!)

What is the difference ?