I would go for the world tool before they only sell it on a tablet or something. I've never used the World version but it looks to be a copy of the original PCD that I have. The company I work for has a PC based tool also that works for the 2000 too, the nice thing about that is when you change displays, it changes the labels of the bits to match so you don't have to refer back and forth to a book. I made overlays for the different displays for that reason but don't use them as much as I thought I would.
Whether or not that tool works for Ascension 200 or not might be an important consideration for which tool you go with though.