You can push more power to your speakers. More power can sound better, yes. It can also support louder volumes without clipping, especially at the low frequencies.
With my old speakers, whenever the bass got really heavy, I would get this sound that I could only describe as floppy. There wasn't enough power to move the driver exactly where and when it needed to be to produce the sound. This can also be damaging to your speakers. I actually thought this was just a limitation of the speaker itself. I ended up getting a new receiver for HDMI, rated the same wattage per channel as the old one, and it also made this sound. But when I finally set it up for bi-wire, and the low frequency had a dedicated 100 watts all to itself, it no longer made that horrible sound when the bass got heavy.
So, in short: Yes it sounds better.