Ok, please bear with me. I am NOT an electrician, but I do all my own wiring, and have installed furnaces and 240v central A/C's (part time) for the past 21years.
I beleive the power cord and internal wiring of most electrical appliances is rated to handle 15A and thats it. In fact most of them will never draw anywhere near that current. The circuit breaker in your home is designed to be the weakest link in the chain. If you plug that appliance into a 20A circuit, then the wiring in the appliance is now the weakest link. What happens if said appliance develops a dead short? It is relying on your circuit breaker to trip. If it doesn't trip, then the heat will continue build inside the appliance until something weaker BURNS OUT. Read **POTENTIAL FIRE**.
You could run heavier wire if it makes you feel better, but I certainly wouldn't put a bigger breaker in.
Sidenote - Most electronic devices have their own built-in fuses, so my "Fire Scare" may not apply. I still wouldn't install the bigger breaker though.
Epic 80/600 + M3's + Custom Finish Algonquin V3's