If you do try it, try to get a bottle of Excel too. I wish I had enough knowledge to do that when I was using the stuff... just to have a basis for comparison.
But as I said, I thought my plants perked up a bit at the time, but who's to say? A nice A:B test against a proven product like Excel would be a nice thing to see reported.
I'd try it myself, but I've got pressurized CO2 on my 75g. And unfortunately I use Excel on my 20g grow out tank, a tank that I virtually ignore. If there was a difference, as little attention that I pay to that poor tank, I'm not sure I'd see it.