Hey Abner,
My overall opinion of Clojure is mixed but positive.
Clojure is quite an opinionated language (functional programming, immutable by default, data oriented, etc). These opinions tend to benefit long running applications that deal with lot of information and multithreading.
A lot of the insights you might gain from Clojure could be gained from any functional programming language in my opinion. The most interesting/unique feature of Clojure is REPL based development, that when used properly can lead to a really tight programmer feedback loop. Other languages support REPLs, but it tends to be easy to get into an inconsistent state because of mutability.
Clojure tends to favour immutable hashmaps and vectors as a way to represent data. Rick Hickey has some talks on why this is a good idea, but I think the focus on data as a way to model a problem more simply is well expressed in
this talk.
Clojure has a bunch of downsides that aren't really ever discussed in my opinion:
1. The solution to every problem tends to be more abstraction. Most people who use Clojure has little idea of how things are implemented or what to do about things when they go wrong.
2. Clojure is pretty fast for a dynamic language (2-4x slower than similar Java) and takes the stance that "memory is cheap", but when you run into performance problems it can be incredibly hard to reason about (see 1). Doing low level stuff is possible but awkward and tedious in Clojure.
3. The community has gotten worse over time. In the beginning there were a lot of smart, humble people working on hard problems. Maybe it's because there are less scientists and more enterprisey web development types in the community nowadays, but fanboyism is rampant and critical thinking relatively scarce.
To be fair, I think that many communities have similar problems. I'm interested in getting closer to the machine but one of the things that I really like about Handmade Hero is that Casey calls it as he sees it without any kind of agenda. He challenges bad ideas and that is a rare thing nowadays.
Feel free to hit my with any specific questions about Clojure if you have any now or in the future.