The charging rate can also be manipulated by the manufacturer. My LG Spectrum comes with a 0.8 amp charger but the phone will not draw more than about 0.5 amps. A custom ROM can change this, with a shortened life span being the result.
Three hours to go from 10 to 100% sounds pretty good to me, though. And when you unplug the phone and plug it back to in charge it some more is called "bump charging." You can improve you battery's charge quite a bit doing it this way, but it can also shorten your life span...
Sent from my LG Spectrum using Tapatalk 2.