Well I personally won't go to 400 ISO unless I'm desperate, I usually get poor results.
And here is what I"m talking about when I say other brands have good ISO modes.
This is a shot taken by a user in the Sony forum with a Sony R1 at ISO 3200.
I can't even see much noise besides on the dancers black pants.
That same shot with ISO 400 on my Kodak? It wouldn't even be usable. I don't mean to complain, the P850 is a great camera, but the ISO is one thing that dissapoints me.