AE Rack 2 vs Behringer System 100 bundle vs VCV Rack

Welcome. Of the bat; the behringer rack you show in your post does not even come close the a AE starter rack 2 in functionalities. The only module I would add to begin with is a multi fx module. You will have a happy little rack with plenty of patching possibilities and exploration and you will be able to make some big sounds. VCV rack is indeed cheaper if you don't count in the price of the computer but for me it never had the same appeal to build a patch on a gui. My two euro cents.

I was interested in modular synths for many years, and even started a system by a defunct manufacturer. The Eurorack standard has made the whole modular thing explode over the last few years & was getting ready to start my journey (again) when I saw the AE. I could buy a whole system for the price I was going to pay for a case and power supply...  AE is not crazy expensive for what you get, but it still mounts up as you expand your system, mine is now my most expensive piece of gear in my studio but, of course, did not have to be paid for all in one go.

If money is a concern, I would forget Eurorack; this is not a cheap way to synthesise.....

The big question becomes why do you want a modular synth.  If your main aim is sound design, then many synths can fit your need and, depending on the model, would have the advantage of patch memories rather than just being able to work on one sound at a time. If you are after more control over how your synthesiser works/is connected then yes, go modular! If you are not needing it to be a self contained instrument I would suggest you could even go for a AE rack 1 but maybe get a 2 row case ready to expand (you are very likely to want to....). The obviously reduces the initial cost and, even better, you can see what modules you will need for what you are trying to do. 

I don't know VCV rack as I don't have a computer is my studio but if you are unsure whether to take the modular plunge it would make sense to try with it first; if you are happy having computer plug-ins etc. then you may even find this is enough for you. 

You are right, a lot of interesting stuff there! I see that AEM is quite versatile. 

A few thoughts
Vcv rack is cool to learn basics while mostly free and as long as stick to the basic modules. Omri Cohen on YouTube has some great tutorials.
I found that I became easily confused with a load of modules that don't come with clear instructions or labels.
Also the feel of a software synth just doesn't feel like an instrument to me.

Semi modular like the Behringer neutron or crave are great to a point but again as others have said you are limited and when you find you need more the cost of adding to that semi modular for probably another semi modular synth will add up way more than buying another Ae envelope or FX or cvtool etc.

I recommend Ae because you can do just that, add one piece of sound design when needed for not too much money compared.
Also compared to Eurorack or vcv, while expanding a few modules a month there are only a certain amount of modules to choose from all in the same design manner with a wealth of knowledge and tutorials for each piece in the community.
As Pt3r just said he and a few others are also designing modules which means that the Diy cababilities for Ae are endless to adapt to your own sound design preference.

Once you get your hands on a starter rack you can do a lot already and your knowledge will grow quite quickly.

Hey pt3r, exactly, that's the main reason I'm interested in modular synths. For example I love sounds of JP8000, Minimoog, Juno-60, but even so they provide nice palette of great musical sounds, they'll never come close to the variety of sounds you can get by using fully modular synths and I'm also very interested in creating SFX sounds like explosions, sci-fi guns, drones, impacts, aliens, creatures for using on their own or layering with real-world recordings and I see a lot of sound designers in games/films use modular synthesis, I guess it's not happy coincidence. As to my knowledge I'm not very experienced with sound design, SFX's and electronic music creation, still quite new territory for me. I come from more traditional music composition/recording/production background, have general understanding of how sound works, know how all base effects function and how to use them (in music production mainly), play piano/keys and bass/electric/acoustic guitar, know how to tune pianos (that's where I first became aware of strings inharmonicity and partials , I also already know what basic modules do in synths like VCO, VCA, VCF, noise etc., but still noob/beginner level I think I was looking at Neutron as a starting point as well, but I suspect I'll want something more sophisticated soon after getting some experience, so why not to start with modular initially. The price is quite comparable to Rack 2 and it provides much more space for exploration, that's my thoughts at the moment.

Pure Data is on my to-do list. I know Python, so shouldn't be too difficult to deal with other language I guess.

Could you recommend any good sources for starting with sound design and modular? For now I've found some cool YouTube channels and creators on Patreon, also reading Patch & Tweak book right now.

Thanks again for your help!

You might want to check out this book "Designing Sound" by Andy Farnell. It teaches a software synthesis program called Pure Data and how to use it to create all kinds of sounds: Sirens, Explosions, Wind, Footsteps, Alien Spaceships, you name it.

A great way to learn synthesis and sound design ... and Pure Data is FREE!

mitpress.mit.edu/books/designing-sound

With the AE or Behringer thing I'd go AE purely from the PoV of supporting Robert over Uli. I'm not anti Behringer but I'm much more inclined to support a small business doing it their own way.

Hiya, for the sort of work you have described in other posts, most monosynths can do it; I would have a look at the Minibrute 2, very versatile and has a patchbay you can use with the AE etc. later. I personally love the Bass Station 2 which is way more versatile than it name suggests (and has patch memories); they have very different character to each other so one may suit you. 

I like the Neutron, preferred it to the more expensive Moog offering! I don't feel its as versatile as the two mentioned above. If rack mounting/no keyboard appeals to you then I would suggest looking at the Behringer WASP - better at noises than music! The CAT may be worth a look too but I haven't fiddled with that one. The Korg Monologue is quite interesting also, especially if you want rhythmic/arpegiator type sounds.

Whatever you decide, hope you enjoy.