A friend and I conducted our own "break tests" between Berkley Vanish and Berkley 100% using a digital scale. We did this because we had just started using Vanish and were very disappointed in it. We each had some 100% left over, so we decided to compare them. The verdict? Vanish sucks! It consistently broke before the "test limit" printed on the package. But we weren't completely happy with Berkley 100% either, so after reading a lot of reviews of various floro's, we purchased BPS's XPS Floro because it was competitive $$wise and had great reviews. We both love it. It even looks/feels thinner and doesn't twist as badly. All floro's twist. It's the nature of the beast, however, XPS seems to have much less of it. I don't see myself changing anytime soon.
Just my 2 cents.