Differences between the two are probably unimportant. Commercial rasterizers are available for most platforms, many are also built-in to printers and plotters. A low quality free rasterizer is available for most platforms in source form inside Ghostscript. Since X11R6 it is compiled into the core X library. Partial downloads are not possible.
Some compression is possible.
There is no software for creating original fonts in TrueDoc fonts directly. Instead, the TrueDoc encoder is given a bitmap of a particular glyph and fits its own curves to it. Each glyph is described as an outline, using cubic Bezier splines. Ligature substitution is not recorded either. How many hints and of what type is not known.