I used Acropower when my tank was new, and I did see noticeable results in color and polyp extension.
IMO, these type of additives are helpful for new and/or ulns tanks. The trend in modern reefing has been ulns tanks and then they sell you all sorts of coral foods/additives to get the nutrients back (ex. Acropower).
I found that when my tank passed one year and started to get seasoned, my Nitrates started to rise (the first year they were essentially 0) and then held firm around 15-20ppm. Since then I stopped dosing everything and my coral colors stayed excellent. It's been about a year since I stopped dosing and I see no reason to go back. Enough fish to keep my Nitrates up, GFO to keep my Phosphates down, proper dosing of the big three, and I'm good to go.
Ask someone with a really nice SPS tank what their Nitrate levels are at and they'll usually give you an answer like, "I don't know, I don't test."