I am thinking about buying a Pentax Digital Spot Meter as a companion for my Pentax 67. I make a lot of pictures in low-light situation at night and thought that the LED-Display of the meter would help me there. Also I am currently looking into getting used to the Zone System. What do you think about this meter in my situation? Is it good with the Zone System? What about its low light sensitivity? What are generally the downsides (if any) of this meter? Is it worth its money?