Fenix 6s vs 5s: what are the differences? Worth upgrading?

Can anyone elaborate on what the real differences between the Fenix 5s and 6s are?

I understand the 6s is slightly slimmer and should have a slightly better battery life.

Apart from that, is there any other material difference? Radically different software? More stable bluetooth connection?

Or is there, in reality, little to no difference, and no point in upgrading?

Thanks!

PS I am talking about the "s" versions only - not interested in the bigger versions