This is my first time using wireless charging and the convenience can't be understated. It's not so much that you don't need to plug a cable in, it's more about the fact that it's charging nearly all the time, which means you're never really worrying about the battery life anymore. Before, you'd set your device down on the table, only bothering with the cable if you knew you needed to charge your batts. Now, you put it on the charger instead so it's always charging regardless. The battery, therefore, is always being "topped off." When you return to it or whenever it is you pick it up next, you're 10, 15, maybe even 20% more charged than before (the amazing thing is it charges pretty fast). You're never really worried about battery life anymore.
It also eliminates messy USB cables. Even though the wireless charger itself has a cable, it's always tucked away behind the charger. It's never "loose" so to speak. You're never tugging for it or looking for the end of the cable. Now, there's just this one designated place to charge your device. Plunk it down and you're good.
It's really nice.