Howard
I can tell you a bit about CGM as I am fortunate to have it full-time. My consultant cares more about his patients than the hospital's overdraft. Having trialled the sensors over a few months here and there I decided they were definitely something I wanted to continue with. So, my consultant applied to the NHS Exceptional Funding panel (every PCT has one), and in short they finally agreed. But I'm the only one in Bristol (out of 80 pump users) so I'm very lucky in that respect.
If you listen to Medtronic, the sensors last 3 days each and cost £40. In practice they can last much longer than that - I've heard some get 14 days out of one - but I replace at 6 days to avoid any site infection, which still halves the cost.
The sensors don't replace testing, they're not consistently accurate enough yet and require regular calibration with a meter reading. But they are invaluable to me as I have zero hypo awareness. Useful too for tracking reaction to different foods and insulin combinations.
Progress is constant however, and I think we may see the first "closed loop" systems appearing in the next few years.