"The Unreal engine as a whole isn't incapable of doing fairly large outdoor areas - examples can be seen in U2-XMP."
Some of the UT2004 maps were enormous to the point that they had to reduce their size because their size was detrimental to gameplay. XMP != 2004. I assure you all, after playing UT2004 at a lan party at an Epic sponsored event that UT2004 delivers in its gameplay, at least in the onslaught mode(didn't get to play assault).
This comment was edited on Jan 25, 16:30.