The TC model A is a MUCH better brush than the 100sf. While being older, they did a wonderful job with the brush, as it's design lasted for over 60 years, with only very minor changes. By the time Badger took over production of the parts, the brush had been dumbed down to reduce production costs, and the performance paid the price for it. I have 16 or 17 Model A's spanning about 45 years worth of production, and maybe 8 or so model 100's dating back to the mid 60's - the 100's just don't offer the same performance, and never have.
With that said, the 100's do perform the way they were intended to - they are OK at what they do. If you are looking for the "best" detail out of a Badger, look at anything that uses the Sotar type head, meaning, Sotar, or Renegade series brush. Next in line would the the Xtreme brushes - at least for me.
Edit: I will add that Badger was a tool and dye maker that wound up being a contractor that produced parts for airbrushes, before they were an airbrush manufacturer. I prefer the older TC Model A's - pre contractor change, as they tend to work better. I have 40's, 50's, and 60's samples that work as will as anything. 70's and 80's, not quite as good, at least not among the samples I have tried (purchased a few new in the 80's).