Icon makes descent quality stuff. The helmets are actually HJC's rebadged. That would put them somewhere about 2/3's up the ladder. They are better quality than the cheapies like zeus and bell, but not quiete up to par with the heavy weights like shoei, arai and suomi.
Their grear does what it advertises well, but it doesnt advertise much. In other words, Icon does not sell track gear. Its meant for light street use, but it handles those duties well, quality stitching, and good comfort. They also have the largest selection of styles.
For my money, I'd pick up a race jacket from technik or alpinestar. One that offers precut sleeves, leather exterior, CE approved armor in elbows, shoulders, and a back protector, together with a higher range helmet. However this is a personal decision, I'll sacrifice some style/comfort for more protection because falling hurts more than dressing like racer X.
While you are out looking for gear, dont forget about gloves, boots and pants. Gloves are second in importance only to the helmet. Roadrash on your back sucks, but not being able to use your hands will put a serious hamper on your life. The tendants in your hands are only about an 1/8th below the skin, and they heal very slowly.