distings can be used for lots of things - including almost everything I mentioned (not sure there is a granular algo) - I really recommend that you read the manual of every module you are considering buying before you buy it - otherwise you will be buying modules that do not do what you want them to - possibly confusing different types of module etc
but each disting can only do 1 thing at a time - unless you get the ex which mostly works as 2 mk4s - although some algos use all of it at once
for a complete basic synth voice you need:
a sound source (a vco), a sound modifier (a low pass filter), a modulation source (an lfo/envelope generator/function generator), a way to listen (I'd use a quad cascading vca such as veils to start with) and a way to play it (sequencer/midi->cv/cv keyboard)
I also strongly recommend links/kinks/shades as a great starter utility set
for a modulation source - I always recommend Make Noise Maths as it is a brilliant learning tool, mainly because of the 'maths illustrated supplement' it is a guide to self patching (patch programming) maths with 32 illustrated examples - a great way to learn modular thinking and patching - working your way through the supplement a few times is a great learning experience - in fact I'd usually recommend this as a first module to go with semis - it will replace both the doepfer dual slew limiter and function generator and add a second function generator and some other useful functions - and only take up another 4 hp
I'd much rather have Doepfer modules (I have quite a few actually) than behringer (I have none) - they are inexpensive, but have a much longer track record of manufacturing eurorack modules - Dieter invented the format - Uli seems to be an ass - not just because of cloning everything and anything (and sometimes in a dumb way - exact clones of early synth modules are not always totally compatible with other eurorack modules etc)
nb personally I wouldn't want a doepfer midi->cv module (I've heard some people have difficulty getting them to work - not sure which ones though) - I'd want more channels though
there are many other inexpensive brands - and some more expensive brands make modules that are more than worth the extra $/€/£ - due to combining functions cleverly
at the end of the day it comes down to do you want to support the big company with poor ethics, or a smaller company with (at least slightly) better ones - do you want to give your money to the original designer (if possible) or do you not care
personally I prefer smaller sometimes more innovative companies (Doepfer is 4 people in Germany, Mutable is 1 in France etc etc) behringer is 1000s mostly in China
behringer quality appears to be poor (nb this is based on watching a few videos and reading forums, I've never seen a behringer module in real life - although I have seen other products from them that were poor quality in the past) - they use stickers on their knobs that have a tendency to fall off, print on panels that is easy to remove etc etc
as always when something appears on the market and appears to be significantly cheaper than a lot of the competition - the 1st question should be how?
economies of scale - behringer can achieve economy of scale like no other synth manufacturer - partly due to their size, but also due to the fact that they own factories that manufacture a lot of 'reissue' chips - which they and other manufacturers use
quality of components - most module manufacturers use thonkiconn jack sockets - these have nuts for the front panel - and also use pots with nuts to hold them to the front panel (and put knobs on them that don't fall apart, see above) these hold the module together well - behringer uses neither from what I can see - they'd be much better if they had spent an extra 2$/€/£ on panel components and charged an extra 10$/€/£
cheap manufacture - behringer is effectively a fmcg company - all their manufacture is in china - most modular companies either build themselves in their garage or shed or attic - or get stuff fabricated locally - Mutable uses a fab in france for example
"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