Funny, I waited forever before nuking the invites, I finally did last night, and you were the first one that ever responded to that post. The invite might not be there anymore if you didn't catch it already.
I still rarely see more than one or two people on live from here when I'm on. With the new Messenger integration I can see a lot of people I found here play during the day and earlier in the evening, which surprises me.
I won't be playing much besides NFL 2K5 until Halo 2 comes out, I would guess. I don't have either of the games you mentioned.
UMR on HDR vs 4K: The benefit of greater saturation and luminance capability is...not very evident in all images unlike more pixels which can be seen in every scene.