I agree with proper battery Redundancy, other than that if your receiver or servo fails a powerbox is not going to help you out. too many connections hard to trace, firmware updates etc.
I had a lengthy discussion with one of the radio reps about powerboxes, if JR or Futaba thought they were necessary they would build them and get a bit of the market. (they do build receivers with dual battery inputs so they agree on that)
There are some very large complicated builds that might make sense for the multiple channel outputs but for most Jets/planes I feel they not required
But it is still a hobby we do what we want to make ourselves happy and comfortable
my 2cents
Regardless, Pete glad you didn't go up, that is one beautiful jet, look forward to seeing it in July
AM