I think something that is also important is simplicity, which is why I believe the pentax digital spot is still in high demand. I recently picked one up and it just clicked. The speed, simplicity and consistency in which I was able to pre visualize my exposures felt almost like magic. I was stumbling around trying to use the zone system with a incandescent meter and was only getting a third of the info I needed. I believe the sekonic spot meters would be a good option but they just had a ton of options that I would never use and don't need to be stumbling around to find the information that I need.