I don't like the taste of the paint anymore myself, as compared to my previous car wash soap. Not as smooth, and my tongue kinda gets bogged down, when dragging the surface of the paint. But it was good for buffing the bishop, but after using it for a while, the damm thing went off.
heh heh, all kidding aside
You can use any soap in it, and it still works well. The only problem is that the filter only lasts for what amounts to several minutes. By the time you have rinsed two cars, you need another $6 filter. Which isn't too bad, if you only use it on your nice cars. But for a fleet like mine, (yes, I know, I'm sucha bigga wheel now) its impractical.
One other little issue, as the filter gets loaded up, it works proportionally less, and there are more and more spots after drying. To avoid any possible spotting, you have to quit using the filter when it has only done maybe two cars, and quickly at that. If you are in the middle of the second car when the filter begins to get loaded up, you get slammed with spots when you are done. So really, it seems like its only good for one good thorough car wash, then you better change to a new filter before starting the second car.
Maybe I'm rinsing too much?