I really like having a monitor on my truck. I use the Edge Insight. Gives me a hands-on view of what my motor is doing, as well as diagnostic tools. I can read and reset codes. Handles a ton of different parameters, but the pic below shows what I typically leave it setup for. Except that the lower right battery voltage is usually showing my trans gear and TC lockup state.
The EGT is less important than some of the others. Particularly ECT and EOT, and the difference between those two. If that oil temp climbs too high on you, you've got overheating issues. You can change gears or slow down and stay out of trouble. Same with EGT. As for EGT, mine will hit my alarm which is set at 1,350 degrees, but not much more than that. Fuel pressure is critical to injector life on the 6.0. The stock 6.0 does not monitor EGT or lift pump fuel pressure, so those are sensors which you have to add. Everything else on my Insight is reading stock sensor parameters. Also, in case you didn't know, the temp gauges on your dash are dummied up. They do not show actual temps of anything. Basically they are just idiot lights made to look like gauges.
Having said all that, unless you are willing to do the homework and learn what all the temps mean, and limits that need to be respected, don't bother getting a monitor. Love my old school 6.0, but you cannot afford to be an ignorant owner.

