225 isn't really that much. You have to train a bit to reach that point, but I see guys in the gym that bench 315 as warm-ups. What they do at max is just sickening. These guys are simply huge.

But ya, man if you continue training, add some bench presses and such. It works your chest, triceps and shoulders in 1 sitting. Pretty efficient exercise. Curls is an isolation exercise, which would only work biceps and forearms, but nice if you want to make those pistons sharp, but it doesn't really add much unless workout triceps and shoulders for full arm definition. You should keep going. Curling 50 is definitely impressive, even when I was in prime shape, I couldn't recall lifting a 50lb with each arm. Damn.