ivan, the evil is also quite long in the top tube, 23.75 ish for a large if i remember rightly. not going to get a good deal on a 2010 one for a while i wouldnt have thought. of the two.
for a slack, solid ht id go for the bfe, especially with the dh sessions in mind. im sure the p7 would be better for all round xc but from what i know of the previous version its no lightweight so the bfe probably wouldnt disadvantage you any in those stakes, especially if you had a u-turn fork on it.
so yeah, bfe!