personally I would like an insulin delivery system built into the same device as the cgm
Take a wristband for example:
1) it adapts to the size of your wrist and is fully flexible in that respect
2) a small cannula is attached to the underside of band where an external port is fed through the band to the outside
3) the cannula is implanted into the body permanently or until a viable replacement offers itself up
4) instead of the wristband storing insulin, you carry it around and when you need it, you just inject it into the location of the band where it will travel to the cannula and then into the body. A portable IV drip if you like.
It's discreet, injecting would feel more natural, some may still prefer to do the old injection and finger pricking, but maybe this could be an idea for the future? And with the small microcomputer within the band detecting blood glucose levels as it is coupled with the cannula that is inserted into the skin, it would display your level in realtime, sounds like a cheap option to me.