Much like the Manfrotto 244N Variable Friction Arm, this is a brilliant bit of kit.
However there is a big and important difference between the two, and that is how they tighten.
Firstly (and less importantly), the lever sticks out somewhat and could get in the way.
Secondly, when you tighten this arm to a locked position, the lever jolts and this is a real issue if you are carefully positioning a camera on the arm and trying to get fine tuned framing.
If you only need a strong arm to roughly position something within a few cms then this is fine. Great for lighting, but if you need to be quite precise, you should buy the Manfrotto 244N Variable Friction Arm. In fact I would go as far as to say, just get the friction arm regardless, as I prefer it.
That said, this lever locking arm is also very solid and it will last a lifetime. It's a great piece of kit that is incredibly useful and easy to use.