yes, some of those other sheets are rather complex and have a bit of a learning curve if you wish to use them to their full potential. Although I have explored most of the features of David Deweys sheet in the past, more often than not, I usually just run a beam test on a sample of the wood I am using to get a look at MOE and set, (to estimate a Design Strain value), then get a basic idea of the shape required before roughing the bow out. I then do most of my build and tillering in a conventional manner, but it is interesting sometimes, to go back and compare the finished bow with the design dimensions on the spreadsheet.
Actually, now that I read over JoachimM's post, his sheets ability to compare length with width and draw weight at a particular strain, is pretty much all I am trying to do with DD's sheet, that is, see what the stave is capable of before deciding what to make out of it.
Never have looked at the arrow speed or energy features, as I have no chrono to verify with. But I will venture the opinion, that if you start with a good piece of wood, the exceptional bow is predominately a product of careful tillering, and having a good idea of what your stave and design is capable of, is a good place to start.