As far as robust, the bulbs are plenty strong. My P60 bulb has been in my light and burning bright for over a year and a half now. I have dropped the light numerous times from heights from 3-10 feet onto concrete with no problems. Looking at my flashlight you would be hard pressed to tell it from a new one. The aluminum construction wouldn't pass the same tests. The aluminum will dent and scratch. No paint or powder coat on the G2Z. MUCH more durable. Also more waterproof.