Hey Graham -- great post! The Medtronic / Guardian sensor combo is generally disliked by patients, though (in the US) the Medtronic 770G is FDA approved for ages 2+.
The bleeding edge is the Beta Bionics (https://www.betabionics.com/) bi-hormonal system (insulin + glucagon), currently in clinical trials for ages 6+.
Most prefer the t:slim X2 with "Control-IQ" (their hybrid closed-loop: https://www.tandemdiabetes.com/products/t-slim-x2-insulin-pu...), which is FDA approved for ages 6+, and works great.
The bleeding edge is the Beta Bionics (https://www.betabionics.com/) bi-hormonal system (insulin + glucagon), currently in clinical trials for ages 6+.