I've heard conflicting things about core work. Some say weighted core work is better, others state that weights will add unnecessary bulk to your waistline which is not my mission, lol.
I usually only use weights when I do the tree trunk exercise for my obliques and sometimes I'll put a dumbbell between my feet when I'm performing reverse crunches. Other than that, it's non-weighted all the way. I've gotten good results thus far.
What do you do - weighted, non-weighted or both?