It allows you to turn down the sub level in the AVR, (negative zone is preferred) and you don't need as much gain on the sub amp for the same output SPL
At reference volume levels you'll have more headroom and less chance of clipping the signal.
So Better? Yes, most definitely!
Oh. Definitely going to look into getting one then! What brand would you recommend? A Monoprice version, or pretty much any Y Splitter would work?
Also, it’s as simple as it looks, right? You put the subwoofer cable into the Y Splitter and then the Y Splitter into the L and R of the subwoofer?