Off the top of my head it looks like you can now (using hydras) get a naval offensive nuke equivalent to 335 light ships which also has the defensive strength of 446 biremes!
It will take time, favour and co-ordination between alliance members about which God they worship but using this nuke you can attack and support better than by using ordinary light ships and biremes (greater attack/defense per farm space than both), also forgot about ever having your naval offensive nukes backtimed as it would be suicide for the attacker, finally it will also create additional confusion about what attacks are hydra and what attacks are c.s. (this of course also being a disadvantage in terms of the speed of the hydra).
This calculation was done using my old naval offensive city (11642 Points, 950 FS) which was the template before hero world features got included in all worlds. So expect this nuke to get even stronger when I include the extra farm space.
I believe that if you have the time to build your nukes then hydra are now essential and should be adopted universally.
Orpheus can give you a double CP .....
True but by the time you need this benefit in terms of development one could argue that you'll have made those coins anyway. I'm only speculating though because obviously I haven't any experience with the system.