Oh damn! I've been theorizing to my friends about a language like this. Assuming that linguistic relativity[1] holds true, this would be super cool to learn, and potentially highly effective as a form of communication. The author goes into this a bit in the FAQ[2]

Probably super hard to learn (if not effectively impossible)... Is there any "native level" speakers of Ithkuil? Seems unlikely, since even the author hasn't learned it fully.

[1] https://en.wikipedia.org/wiki/Linguistic_relativity [2] http://www.ithkuil.net/faqs.html under "Some people have claimed that using Ithkuil, a person would be able to think five times faster. Do you believe this?"