If one plans to use the lib in the browser, it makes a huge difference.
Also, I'm not a crypto expert by any mean, but SJCL seems higher level, and hence, easier to use. Not to mention harder to missuse.
Projects like https://0bin.net have been using it for 7 years, with 500000 visitors in the last few months, so I'd say it's pretty battle tested too.
Not nearly has much as libsodium, of course. But I wouldn't discard SJCL, I think it has a place.
The documentation is centered around that one simple example, and the library doesn't seem to do a lot else (at least through a high-level API). I also have a problem with NaCl/Sodium forcing users to handle nonces, rather than handling that detail internally by default. Besides that, Sodium isn't particularly more difficult to use than SJCL; the whole point is that it's an easy-to-use high-level interface that's hard to misuse.
I would also note that SJCL's defaults are a bit dated (CCM vs GCM, 128-bit vs 256-bit, PBKDF2 vs a memory-hard KDF like scrypt or Argon2). Additionally, being pure JS would raise concerns about side channel attacks more so than WebAssembly (like libsodium.js) or native code (like WebCrypto).
I'm sure there are simple use cases where SJCL provides some value, and I'm not saying data and applications that depend on it out in the wild should necessarily be considered already compromised, but I'd struggle to think of a situation where I would consider using it in a new project today, over either libsodium or nothing at all / just TLS.
Presumably it shares the downsides of TweetNaCl ("doesn't wipe internal buffers [...] [and] has two harmless instances of undefined behaviour"[1]; among, I expect, other shortcuts that may make it less optimal/safe than NaCl), and the fact that it's pure JS adds additional side channel attack surface, but those may be acceptable risks depending on your threat model. They're certainly the least of your concerns if you're just using it in a web page like 0bin.net.
Libsodium is a solid crypto library with long history. It is also embedded in PHP,HHVM,Citrine and Factor "out of the box" and has bindings for many other languages, not just Javascript.
In my view, any competing crypto library would have to be something super special to outweigh all the pros of libsodium.
SJCL predates libsodium.js :)
From the SJCL documentation:
> An older version of this implementation is available in the public domain, but this one is (c) Emily Stark, Mike Hamburg, Dan Boneh, Stanford University 2008-2010 and BSD-licensed for liability reasons.
Like interoperating with anything not designed by djb?
Would you say that libsodium.js is better?
node-forge is a good example of giving a user too many options in my view. As a developer looking to secure something, you've apparently decided on AES-256 against options like "DES" and "RC2" that are on offer. That's a good step.
Now you get to choose between ECB, CBC, CFB, OFB, CTR. Which is a good idea? Which isn't? The documentation appears to just say "here is a great example of using CBC mode". That example is vulnerable to a padding oracle (uses PKCS#7 and has no form of MAC). From what I'm reading it's left as an exercise to the reader to record the iv somewhere. If you did want a hash, it helpfully suggests MD5 as reasonable.
This isn't a great example of crypto engineering.
If you need AES in particular, node-forge is probably fine, although from a quick glance it looks almost identical to Node's built-in crypto API, in which case you could just use that, but they both look pretty inconvenient (excessively low-level) to use directly.
Fundamental issues with JS/web crypto aside, that is. You would still need something like WebSign (https://www.cyph.com/websign) or a framework like Electron that allows shipping your application outside of the browser.