Lone Speed,
Agreed - Bill does a great job demonstrating the use of these programs and bringing back to attention all the various concepts that went into them! I know I learn new things about them, even if I do not use those programs anymore, but they do give me ideas for RDSS
An interesting point, re your comments about DTV and ITV variants - if those who use RDSS choose to let it incorporate its TrackMaster DTV and ITV variants and distance projections into an Adjusted 3-call (or soon 4-call) export file, then Entropy, EXDC, Thoromation etc can indeed make use of a good set of variants, and perhaps be even stronger, as you suggest.
best,
Ted