I think so... Tried most of them and always seem to find my way back to IO.
It's cheap, mixes closest to where I keep my parameters, readily available and goes on sale often.
I run an SPS tank. 99% of my Corals grow like weeds. I do dose the big 3 with ESV BIonic, and suppliment here and there, but, for the $$$ I don't know if you could do much better.
Others may disagree, but there is a reason IO and RC are still around, and still cheap.... They sell it by the metric ton.....