If you can't hear a difference, ultimately it doesn't matter if there's a difference or not, but I see where you're coming from by wanting the best just in case.
Bit-perfect plugins like this bypass the operating system's audio mixer and send the signal directly to the sound driver. This ensures that the operating system doesn't do anything unwanted to the signal, like resample it or change the volume. It also gives the audio exclusivity, so that when it's playing no other sounds can be heard (like a YouTube video or OS sounds). The only thing the drivers have to worry about is the music.
There's no guarantee it'll change the sound at all, but it will ensure that your player sounds its best so it's always recommended.
By footprint I imagine he means it uses little system resources. It can also be customized to look and act however you like it, but takes a little effort.