I'm a 38 barb playing with a friend in nightmare right now, act1.

I've been (for some reason) stacking +xp on kills items along with STR.

My question is, is +xp worth the item budget? Do I get enough xp from kills to warrant seeking it? Do you level faster with +xp gear or does the tradeoff of having less damage or survivability make it actually slower what with taking more time to kill mobs and not being able to be in melee range for longer because of the low survival stats?