I think 10% is about right at the moment. I remember one objection to lowering the interest rate from 20% was that it might create a run from HBD to HIVE causing the price of HIVE to crash, and we did indeed see a decline in the price of HIVE as the HBD interest rate came down, but I think there may have been other factors influencing the decline, not just lower HBD rates.

However, the good news is that the HBD debt trend has dropped back to just above twenty percent when it had seemed almost inevitable that it would keep on rising and kick HBD off its peg.

Source: https://hbdstats.com/

That was also helped by the recovery in the price of HIVE, so I think it was right to reduce the HBD interest rate from 20% and to do so in a series of steps rather than a straight halving to 10%.