Downgrade for samsung s5 sgm900f can i do it?

[Android Central Question]

Can someone tell me what android works better on this phone?

 

[Rukbat]

6 has more security than 5. That said, you can flash 5 if you prefer (I'm still on 4.4.2 on one phone because I prefer it). See [Samsung] How to flash Stock ROM via ODIN.