I use Power box Digi-swith in past 3 years on 3 F3A 2 meters ships without a single failure.
Recently I have started to fly new Axiome and I use Power Box Sensor. It is a double separated channels supply completely isolated with 2 separate regulators + auto backup both directions all in one case 34 grams only. There are 2 input connectors for 2 LiPO packs and 2 outputs were 1 is to RX and 2 is to CDI. If one battery voltage drops or goes dead, it will sense and automatically switch and supply from the remaining pack supply to both outputs as a backup. Output voltage on both is 5.9 regulated. I use 2 packs of TP1320 MAH. This will last for 6-7 flights.
Regards
Amram