Russian roulette, my friend. You might get lucky on a first go or you might not. I wanted to upgrade to M3Pro myself. I was very tempted but after going through what I went through with M3 and after reading about your and others plight I simply refuse to take the risk of potentially having to go through the same tedious process of testing, returning and waiting for replacement with no apparent quarantee of getting a good M3Pro, as your and others case is a sad testimony to that.