Down vs. Down Alternative: Which is Better?

i have been looking for a down or down alternative comforter for my two pre-teen boys (this alone, tells you...it's gonna be thrashed in 3-6 months! so i don't want to spend too much money on it. considering it somewhat disposable. ;)  i, myself, love the wool bedding products from Shepherd's Dream, but i don't want to invest that much money for something so short term for the boys. hence, i'm looking primarily at down alternative comforters.