Is Tungsten REALLY better than steel for waterfowl?

My first time water-fowling was this weekend. I bagged 2 mallards so it wasn't a skunk, but i was wondering if the tungsten or HD rounds are really worth the 4 bucks a round ( Ontario ) or if the difference is negligible? The only reason i ask is because there were one or two shots i know were on point, and saw some feathers but the target failed to drop. Is that a issue or do most of you just use steel? Thanks for insight from experienced hunters.