Ann: Recording - Special briefing with Prof. Toby Coates, page-3

Plenty of benefits even if insulin still needs to be administered.

Less insulin may be required over time - which is already a bonus.
It can reduce the need for continuous glucose monitoring.
It would also reduce the risk of severe hypoglycemia (something that diabetics can be very fearful of as it causes dizziness, seizures, coma or even death).
The real benefit is that you get improved blood glucose control over long periods of time with a better HbA1c reading (this test reflects the average blood glucose in the last few months) and this would help to slow the progression of long term diabetes complications of which there are numerous (renal disease, heart disease, neuropathy, peripheral arterial disease, vision loss, infection risk etc.).

I think it was pretty telling that people who were in this trial said they would be keen to be part of any future trials. That goes to show that the procedure couldn't have been too invasive, that they didn't have a problem living with a small patch of BTM, and that they see a benefit or potential benefit.