There is one small issue with DAI in my eyes. It has been trading for a premium, while at the same time you can't make a profit from owning it because the spread is always an issue. I am testing an automated contract that does 3 way arbitrage between USDC/USDT/DAI and it has never once crossed over to DAI, while USDC/USDT cross each other enough to trigger a trade, 1-2 times a day.