Well, I have established tanks but I still do a water change once a week to clear out debris. That is when I use Prime. I use special blend (and nite out, as recommended). It eliminates frequent water changes and keeps my tank completely stable.
Hmm...a once a week water change is all that is usually recommended. Do you mean it eliminates having to do large water changes? You don't post any specs on the tank, but 20-25% is usually enough, some people do up to 50%. It all depends on your biological load. Your higher end pH corresponds with a high alkalinity, more than likely, and that helps keep things stable naturally. If you haven't read this article, take a look:
http://www.wetwebmedia.com/fwsubwebindex/fwhardness.htm
As the title states, hard water can be a blessing in disguise.
Feel free to keep using the Eco Labs products, just know that it's probably not doing a whole lot and is certainly not necessary by any means. If money is not an issue I wouldn't worry about it, but if you're trying to save money in your hobby that's the first thing I'd eliminate.