John, I too am evaluating which light meter to purchase. One drawback of the Sekonic 508, as I understand it, is that there is no viewfinder readout. Therefore, you can't just point at different spots and instantly compare light readings for different spots in the scene, but need to look on the side of the camera after each reading. By comparison, the Pentax digital spot meter gives you instance viewfinder readouts, but lacks some of the other nice features of the Sekonic. Has anyone used both the Sekonic and Pentax? How would you compare them?

Also, the Pentax spot meter can be modified by Zone VI to give what is touted to be much more accurate readings. Is it worth it to get a spot metered modified in this way? Does the Zone VI modification increase the accuracy for exposing color slides in addition to black and white negatives?