When comparing Hy vs MIT/GNU, the Slant community recommends MIT/GNU for most people. In the question“What are the best Lisp dialects?” MIT/GNU is ranked 7th while Hy is ranked 11th.
Ranked in these QuestionsQuestion Ranking
Pro Python interop
Hy compiles to Python's abstract syntax trees. Python can import Hy modules, and Hy can import Python modules.
Pro Easier to read
Distinguished between arrays (or vectors) and function calls by using  and (), respectively.
Pro Copyfree and open source
Uses the MIT (expat) license.
Con Not very well-documented
The documentation is very sparse.
Con Ill-designed interpreter's interface
The interpreter does not support the use of the left and right arrows to move the cursor in the code and the use of the up and down arrows to navigate through the history.
Con Not made to run as standalone
Cannot be compiled to a standalone executable, only to byte code that can be run from the interpreter; and cannot be conveniently interpreted by the interpreter from the command line.