Not bad indeed, very nice even!
I opted for 12 gigs of RAM at first too (it was either 6 or 12), but it would leave so much unused, I spent the cash on a better graphics card.
I got an i7 920 with 6 gigs ram and a HD 5850.. and it runs like a dream.
Yours should run very good too, even though the graph card is a little less powerfull, it can draw on extra power from the access RAM I reckon!!