an antiscuff will make the bat last longer and protect it.
It will usually marginally reduce the performance of the bat, but not always - that is the trade-off - in a way similar to the pressing debate - a one night stand or a bat for life... I have found the helecopter scuff sheets to be great for pretecting the bat, but the kook scuff sheets have a significantly better "performance" and "feel" retention...
the Antiscuff will hold the moisture in the bat, in the same way oiling will.
personally I whack a scuff sheet on out of habit now - I would rather the bats lasted that bit longer - if you get a beauty, you want to keep it for as long as possible, in my world...