Engine/Transmission (1998.5 - 2002) Gauges or Blue Box Data

[hammersley]

Some of the boxes. like Blue Box, or Cummins Road Relay (no fueling option) offers extensive data that looks like it replaces the gauges, so it appears as though there is a cost savings. I know you don't get the Cool Gauge Pod effect, but if you are looking at $$$$$, isn't this the way to go? A fuel box and gauges in one appears great. What am I missing?