The initial release of Vanish was nothing more than gargbage. It broke extremely easily. Unfortunately at that time I bought bulk spools of it, $52.00 each. However, since then, they redid the "formula", and the word is that the "new" Vanish is as good or better than any other Flourcarbon in the market. Unfortunately there is no way to tell by the packaging if it's the "old" kind or the "new" kind. Your best bet is to buy it from a place that readliy moves/rotates its stock, such as Bass Pro, or Cabelas, or even better, buy it direct from Berkely.
My favorite Flourocarbon is made by Seaguar. However, it is a little pricy. But low and behold, BASS Pro Shops XPS Flourocarbon is exactly the same line. Seaguar actually makes the product for them, but BASS Pro puts their lable on it. I know this because I was fortunate enough to fish with Kevin Van Dam this past spring and he gave me the run down on all the Flourocarbon lines and who actually makes which brands.