All the stuff you listed can be done with decent code.
I've not bought too many recent games and not noticed any cloth/fog/object effects, so saying it can be done sounds not very encouraging.
I'm running an R9 290 from Sapphire and a second hand MSI 460 Hawk for hybrid PhysX, to clear up where I'm coming from. I see the thousand objects in Mafia 2, but I also see that performance would benefit greatly from Mantle.