I think both weights lean more towards a true 3 season. Warning: Spoiler! (Click to show)
If I wanted a true summer weight coat though, I would go for the zegna check or indigo wool, which are 230g. Especially if you live in a warmer climate. When it's 80, the lighter the better IMO.
I have the same jacket, which I picked up after you posted pics of yours! :)
I agree. Above 70, it gets pretty warm. Three-season in straight navy would be more versatile, but I expect the Zegna to be a luxe fabric that will deal with the heat well in 80 degree weather. Because I run hot I expect it to still be wearable a lot of the year.