doepfer are great full stop! not just when you are starting out...
I think the more you want to actually do "modular synthesis" as opposed to "just connecting some synthesizer modules together to produce some sounds", the more simple building block modules are important, and even when "just... to produce sounds" the addition of simple building blocks into especially modulation is an inexpensive way to implement complexity - and doepfer are especially good at simple building block modules that mostly do exactly what they say they do
I have quite a few doepfer modules - mostly utilities and filters - and I consider them to be as good quality as any other manufacturer - I've not got an adsr though
maybe some of their modules are a bit poorly documented (possibly lost in translation from german to english) and the odd module doesn't work how you might expect, but the same can be said for almost all manufacturers
and whilst he didn't invent modular synthesis, Dieter did start the eurorack format
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities