M1S Gen 2 and M3 Do I need both?

General
,
1

I started my Aqara journey with an M1S Gen 2 hub and recently purchased an M3.
Aside from the light, is there anything the M1 can do that the M3 cannot.
Do I need both?
What have others done with there old M1S Gen 2s after upgrading?

2

HomeKit news has an excellent article which compares all the hubs, which they update whenever there is a new hub: