I played just about all weekend. It was sort of disgusting. The gf had a girls weekend, so it meant i was left to my own devices...not a good thing when i have the witcher 2 around.
Overall Game thoughts
Let me get this out of the way. This is not only one of the best RPG's I've ever played, but one of my favorite games ever. Its up there with fallout 2, red dead redemption, and uncharted 2. I'm enjoying it much more than any of the elder scrolls games, and that's saying a lot because until i picked this up, skyrim is the game i'd been most excited about because i LOVED morrowind and oblivion.
I'm playing on normal because I'd heard about how hard the combat was. I really wish i would have started it on hard. I think the problem is that the combat plays more like a mash up of diablo and arkham asylum than it does most RPGs. The only ways you really die are if you are impatient with combat.
The one complaint I have about the game, though, is that it has picked up the old school "take anything from anywhere at any time" RPG convention. It wasn't good 10 years ago and its especially jarring now. You can be in a poor peasants house with his kids and his wife standing there and just take all of their gold, cloth, and books and they dont say a word. Strange.
Finally, I have found that it is much, MUCH better to play this game with a gamepad. The game really feels designed for a game pad. In fact, they should have put it under "Recommended Hardware". As much as I love K&M, there is no comparison here.
iMac Performance
As I mentioned before I have a new, 2011 base iMac. I spent about 3 hours with FRAPS going through all of the combinations of settings between 1080P, 900P, and 720P trying to find the best balance between appearance and performance. I would change on thing at a time, perform the same actions, note the FPS, and keep repeating.
NOTE-i did not even bother trying ubersampling. The one time I accidentally changed it, I couldn't even get the game to load. I should also note, however, that it was a 1920x1080 resolution at the time, but still. Don't ever touch it if you are on a base iMac. I also tried playing with setting ubersampling to 1 in the user file. I couldnt' get teh game to run well with that setting at any resolution. I have a feeling that whatever kind of filtering they are doing with that setting is very VRAM intensive and i think it needs to be reserved for the 2gb options (though the 1gb may work)
Rather than run down what each option looked like and performed like I will sum it up by saying that after all of that I came to the conclusion that the best performance:appearance ratio came setting the resolution to 1600x900, textures medium, shadows med, shadow lights med, light shafts on, vsync on, dangling object limit on, rain effects or whatever its called on, cinematic dof on, decals medium and everything else off.
This keeps it playable outdoors during fights at around 25 fps. Inside its more like 40-50. Turning off light shafts gave me a whopping 1 fps difference, and i like the way it looks.
1920x1080 was never playable unless i turned the textures down low and teh downsampling up high and its looked awful.
720p let me run AA and SSAO, but it never looked as good as the 1600x900, especially during dialogue sections where the increased resolution really shows itself on the characters clothing.
Long winded, but hopefully someone gets some use out of the post. Thanks to all.