Ran into another one today, about 15,000ft. I was in a -4 slightly below but had a TON of E (I was making a shallow dive to close on an unidentified dot when a squad mate spotted him at the cloud layer). He HO'ed my squaddie, and as he blew past overheard I went vertical and pulled behind him with an immelmann, ending about 600 yards out. If I pressed the attack I'd have had him easily, but there were a pair of high P-51s prowling the area so I kept my altitude and let him go to deal with the bigger threat.
So far I've not seen anything to really fear from the M. As others have said, it's still a Jug.