I've raced for about 15 years, and 3 of them have been whilst sponsored by Tekin, so I am tied into using their products where possible.
I have every faith in their products, especially after the Tekin domination of the Snowbirds racing

Personally speaking, we have some rather clever electronics, that you can feel the difference with over other brands, and a constant development within the software.
We are learning quite a lot about timing, both on the motor and within the ESC, and how it effects motor temperature.
I'm sure the Novak system has a lot of good results behind it too, but I personally havn't used any Novak equipment since joining Tekin. I liked how the Cyclone TC ESC performed with a stock motor, but could never get the datalink to work with the ESC.