My daughter was diagnosed 5 years ago at age ten. We have used Dexcom through several versions but I can tell you for accuracy and ease of use the Dexcom G6 is hard to beat. As a parent, it gives me peace of mind with all the share features and allowed us to give her more independence even when she was younger (I.e. sleepovers). We did have some adhesive issues with Dexcom when she was swimming, however using Skin-Tac when applying the sensor and occasionally some Tega-Derm for the last few days of the sensor session if it was loosening up really helped out.
We also have used Omnipod for 5 years. She appreciates the freedom without having tubes. Now that she’s a little older we find we can only go two days before having to change the pods out but that’s not been an issue with insurance. We have lost a couple of pods through the years (messed up installation, pod failure, fell off) but Insulet always replaces them without question if you call them in. We looked hard at Tandem T-Slim because of Control IQ, but chose to stay with Omnipod and are looking forward to the Horizon.
As far as cost goes, I highly encourage you to check you pharmacy benefits. We used to get both Dexcom and Omnipod through our durable medical equipment benefit which cost us a few thousand dollars each year. Once they became available on pharmacy benefit, we get them via mail order for a few hundred dollars each year.
At the end of the day, choose what gives him the confidence and freedom to manage his diabetes and not feel like it’s controlling him!