I recently picked up a 2010 X2. I’ve been avoiding using it too much in the mud, but have done a couple of races on it, and a reasonable number of rides. It climbs really well, especially churning away in the middle ring up firetrack climbs. I had an absolute blast on it the last time I took it to Glentress, as it was so much faster and smoother, so I was carrying a good bit of extra speed over the jumps.
I have had a 2008 Epic in the past, but haven’t ridden them close enough together to make a fair comparison. Even with 100mm forks, the Anthem is sure footed enough for me on descents, partly thanks to the 670mm bars. I had a Scandal in between, but it’s probably not fair to compare the Scandal to the Anthem, as they are quite different.
Can’t comment on 120mm forks, but the bottom bracket is fairly low, although not excessivly low for a XC bike.