I would not completely trust USDT, because they are not backed by anything. The DAI project is covered in real dollars. Trust in USDT is gaining popularity in the crypto community and over time it will become a postulate. So far, users have in their portfolio a set of different stablecoins.
That is my opinion on this matter also. I have the feeling that USDT is not totally backed with US dollars. When they admitted before that they are not fully backed, I have the feeling, that they are not always saying the absolute truth about their assets. So just be careful holding long term this stable coin.