I have to deal with uC++ for the term. I'm not quite sure how to feel about it. On the one hand, it does make it a bit easier to write concurrent programs. On the other hand, I would have been more comfortable with Boost or almost any other language to learn about concurrent systems.
FWIW, I really liked it. I thought it was pretty clear and comprehensible. Of course, that was like 10+ years ago now.