Yes, compile times are rather long, about 40 minutes for the full interpreter on a recent, fairly good, laptop. On the other hand you don't need to do a compile all that frequently, because all the code is testable by executing directly atop another Python.
So you develop the interpreter by interpreting it on itself before compiling it to itself by itself.
Uh...
You might have some fun reading about the Futamura projections :)
Am I right in thinking that the drawback of this method is very long compile times for producing the interpreter?