So after some internal debate with Dragon Age 2 coming out I decided to pick up the Ultimate edition for 360. I played about 15 hours on the PC on "Hard", but didn't want to invest in cables and wireless keyboard/mouse to play it on my TV. Plus I plan on playing 360 version of the 2nd so I'd like an import option. 
 
Before I started I was curious how the diffuculties compare? I like a very very stiff challenge, not so hard that you can't play it. But on the PC version of "hard" you had to very tactical, pausing, and a slight misstep was certain death. That or you had to do side quests, and upgrades so that sections would be easier. 
 
I heard Hardcore 360 = Normal PC and Nightmare 360 = Hardcore PC. Is that true or are there other differences behind the scenes that we don't know about?  
 
Thanks for the input.

I find the chaotic nature of the console gameplay makes it quite hard in some cases that would require a lot of coordination/spells&talents from your party. in the brecilian forest, where you have to disturb the tombstones to make revenants appear, I found it impossible to kill the revenant and his posse of skeletons on "normal", for example. my party would be dead so quick, I didn't even have to to reposition them individually and/or activate their talents. I did that while being level 10ish with everybody, maybe that's the reason.

Console version is quite easy compared to PC version, though you still cannot be reckless.  You're pretty much right on in your comparisons.  Having played both versions, I found the PC to be a greater challenge but a lot more fun.