Problem with TC is, the true relationship between temperature and resistance of a sensing wire is a curve.
You cannot input a curve on a mod with three buttons, so all the mods except DNA use a number called TCR. Geometrically, a single number is a flat line, not a curve.
The impact of approximating a curve to a flat line, is the temperature shown on the mod is an approximation of the reality, which gets more and more incorrect as you depart from median temperature.
Once you grab the above, you are either happy to vape with a mod with TCR, or you want precision and repeativity, so you turn to DNAs.
It is a limit of technology, which uses alinear materials, and requires a computer if you want precision.
Having both DNA and Yihi, I would say you few things.
First, Yihi uses TCR not a curve, so the temperature shown is an approximation, and the changes you make, are not linear.
Yihi uses the Power setting in TC to pulse the coil with it, while DNA intend it as a limit to the power fed to the coil. This is a big and fundamental difference.
The DNA approach is the one most correct, but some prefers the brutality of Yihi approach, as it seems more powerful.
In my view, if you set the power too high with Yihi, it starts PWMing the coil, which in turn affects your wicking. This doesn't happen with DNAs.
My preference goes with DNAs.
I love the DNA250C too, but I'm also a big fan of the JoyeTech model. The JT has an advantage of being able to use either TCR or a temperature curve. It also has the advantage of cost--you can get a powerful, reasonably accurate and highly customizable JT mod for the cost of just the DNA chip.
The DNA samples the coil resistance much more frequently so while its model is curve only, it's better able to adjust power during the drag/draw/pull/puff. I like that a lot because it means a smoother vape. The DNA is also slower to reach the target temp (without "punch" turned on) so you never even get a hint of overheat.
If I were to show side-by-side plots of the power vs temp relationships for a DNA250C and a JT200, the power and temp plot for the DNA would be much smoother than the JT. The JT plots are more ragged because by the time the chip samples coil resistance, it's already too hot/cold and the mod makes a larger adjustment in power.
Mods that use TCR only are fine as long as you're in a range below 470F (245-ish C) and you have the ability to fine tune the coefficient and starting wattage. For a 6-8 second drag, a straightline curve via TCR is indistinguishable from a nonlinear curve model. This is especially true when using SS wire, and you also have juiceflow and airflow moderating temperature change in the chamber.
The more complex the wire and build, the more you want a custom curve.
I've been buried in studying temp control for the better part of 2018. I've used chips from Evolv, Joyetech, Voopoo, Vandy, Smoant, Think Vape, Geek Vape, Kanger, Smok and Wotofo. I don't have a YiHi, Dicodes or AsMODus device (yet).
My favorite is the DNA250C, with Joyetech a close second and Smoant a close third.