Well, yea. It's really debatable. It's pretty much the risks of funds being frozen(centralized stablecoins) versus the price instability and the no guarantee of 1:1 peg(DAI/SAI). It mostly depends on what risk you're willing to take. Personally in the short short term, I'd go with centralized stablecoins like TUSD(because Tether is just too shady). But long term, I'd hold fiat and not neither. I'm still just not 100% convinced with DAI/SAI.