I can see both sides to the argument. If you kick the XP, its an 8 point game meaning that even if you somehow give up a TD, they still have to convert the 2 point conversion, which I think is like a 60% conversion rate. On the other hand if they go for 2 and get it, game over. If they don't get it, the worst that can happen is they tie it with a TD. I tend to side with the XP because I feel so much more secure when my team is up by 8 vs. when it's up by 7, given the odds that they drive down the field and score and then still have to convert a 2 pt conversion.