TC gets a lot of hate among the people that are set in their ways, and simply cannot do it correctly, and have nothing better to do than go on and on about TC being hype and terrible, etc.
Truth is: TC is quite easy yet escapes a lot of people.. you set the wattage for how fast you want the coil to heat up (aka ramp up), then the temperature that you find best for you (which the mod controls to power to not go over it)... nothing more.
The difference is simple, stability: once set, you vape is always the same heat, etc. it prevents dry hits (as once the wick gets too dry, the resistance changes and the chip stops the power output as it's going over the settings). It's a smoother vape overall, no headaches or risk of burning (unless you push it too high/incorrectly)
I use it with my regular tanks, either NI or SS, and use it at times with my RDAs too (but still use watt mode with some claptons I have).
But I know that when TC came out and I was able to try it out for myself, after a slight learning curve to understand it, I absolutely loved it and never looked back. I'd rather TC than watt mode any day.
The other advantages is that :
1) makes your batteries last longer
2) helps your coil last longer (not burning the wick, and coils don't gunk up as fast because you don't burn the liquid - sweeteners)