Obviously there is no electronic downside to using heavier wire. But we should keep things in perspective. Yes, lower impedance speakers do draw more current. But do they draw more current than 14 ga wire can handle? It would have to be a very, very long run in my opinion. One of my hobbies is flying electric radio controlled airplanes. My larger ones use 12 ga wire from the battery pack to the speed controller. Those speed controllers are pulling as many as 50 amps. That's more than an electrical outlet in your home. That's a lot of current. Way, way more than an audio system has to deal with. Speakers would normally be pulling in the area of 200 milliamps or 1/5 of 1 amp. Like most hobbyists, audio guys tend to take electronics situations to extremes. I know. I've been an audio guy for a very long time and I'm actually ashamed of the extremes to which I've taken some things.