There's no best way to add the essentials, it's really based on the tank's needs, skill level and what you feel comfortable using. All of the methods will get you to the goal post. Each method will have it's pros and cons, so there's no "best" method in this regard. For example, you wouldn't put a CaRx on a softie tank, would you? I know someone who uses AFR on a 300g system, but he gets paid a lot to take care of the tank, so the amount doesn't bother him. For me, I think AFR is great for nano tanks and maybe a mixed reef in the 40-50g range. The great thing about it is you only need one doser.