As someone who has vacillated between both tools, here’s my take: it all depends on your goals. Though supernotes and obsidian may seem totally comparable on the surface, I think these tools each excel at solving fundamentally different problems.
Supernotes is optimized for learning. There are a few features/design choices that contribute to this:
- The character limit and card-oriented format forces you not only to capture information but to transform it. This, typically, forces you into a more retrieval-oriented process instead of a lookup or rereading based process. Studies about how we learn suggest that forced, effortful retrieval and information transformation processes like this are more conducive to learning.
- Supernotes emphasizes creating hierarchies in addition to creating freeform networked links. Again, this kind of feature forces the user into a more active form or learning. We are prompted to think about where information fits.
- Supernotes puts sharing at the forefront. This is another design element that makes it an optimal learning tool. Research shows that learning is amplified and strengthened when we make it a social process. I haven’t made much use of these features yet myself as a solo learner, but I hope to do so soon, probably through this forum.
Contrarily, while I think Obsidian is a great tool, I do not think it is as nearly as optimized for learning. Instead, I think Obsidian is a better choice if your aim really is to build a freeform collection of networked writings. If your goal is to actively learn and retain information as you capture it, Supernotes is probably a better choice. If your goal is to build up a large-scale network of arbitrary text with detailed metadata, that you primarily reference directly, instead of using as a learning aid, Obsidian might be better—but supernotes works quite well as a reference tool too.
This is probably a controversial take, but I actually think overemphasis of backlinks is bad. The human brain excels at associative thinking and by leveraging this function of the brain, we’re able to recall more information and deepen the neural connections that relate to a given piece of knowledge (consider, for example “memory palace” techniques, which are highly associative in nature). Use of backlinks offloads this associative processing to our tools, cutting off the brain’s chance to solidify these associative connections. I don’t think it’s bad to have backlinks around for later perusal, but what I would say is that emphasizing hierarchy more during the learning process is probably better. Everyone wants to be Niklas Luhmann and create a hyper-networked zettlekasten, but Luhmann was a unique and impressive thinker. In addition, we need to consider the ways in which analog methods make a difference. Luhmann’s entire system was in paper form, and he had to hand-write his notes. I’m not yet convinced that we can simply translate the same ideas to digital methods with the same effectiveness.
Obsidian has occasionally pulled me back when I find myself wanting to do freeform writing in the midst of learning, but the key here is actually to separate those two processes. Writing on a subject is a great way to reinforce learning, but we can make that a separate step from information capture, and, in fact, this will lead to better retrieval patterns and active engagement.
I do like the data model of obsidian—it’s comforting to know your data can stay wholly in your control, but, if you want to work with stuff on the go, you need to store it somewhere regardless (be it icloud, obsidian sync servers, etc.) so in the end, this is not really an advantage. I’ve also not had any issues yet regarding supernotes data storage or exporting data, which is great.
Finally, I think Obsidian’s plugin system, while super interesting, is actually just a huge distraction more often than not. Supernotes is an elegantly designed solution that works out of the box. Sure, it imposes certain constraints, but as I’ve argued here, I think pretty much all of those constraints are good ones when it comes to learning.
), we’ll all still have complete access to our Supernotes data. 
