ALCA 5 has very similar properties but my understanding is that it machines more easily than Mic 6. I don't have lots of experience with which to compare the two. But I've milled and lathed cast aluminum and didn't find it terribly hard...
When it comes to 6061 vs either ALCA 5 or Mic 6, I'd say different materials for different purposes. (You wouldn't think of wrought steel and cast iron as interchangeable; they are good for different purposes.)
When it comes to 6061 vs either ALCA 5 or Mic 6, I'd say different materials for different purposes. (You wouldn't think of wrought steel and cast iron as interchangeable; they are good for different purposes.)