OK Nick, here's the comparison chart as promised, its only a few of the total published.

Ilford Developers Higher resolution

You will see the main developer types:

ID-2 MQ ID 67 PQ Universal film & paper developers

ID-3 M only Soft working developer for films or papers

ID-20 MQ ID-62 PQ Film & Paper developer (fine grain if used quite dilute).

ID-11 MQ ID-68 PQ (Microphen) Fine grain film developers

ID-19 MQ ID-72 PQ Clean working Industrial, Aerial photography, x-ray developer.

ID-14 Contrast developer, for films and papers.

Of course Ilford have published many other formulae, using other developing agent etc but these give you something to start with, all companies produced a similar range of developers. The commercial version of D19 is more likely to be closer to the D19b variant.