I set it at 20% and advocated for others to do the same when UST was paying 20%. I felt it was important to be competitive in the DeFi space at least on a temporary promotional basis even though everyone should recognize that 20% is not sustainable indefinitely if there is too much demand (we're able to afford it on a small total saving balance as long as uptake remains low due to hardly anyone knowing about it).

Once UST collapsed, it was no longer necessary to pay 20% to be competitive. IMO 15% is still a very attractive return, better than just about everything if not everything else, and saves us a bit of expense on interest. But the 5% difference is not large, so I haven't really pushed for a reduction. The 15% is just my opinion.