DerAdlerIstGelandet,
I'd be interested in reading that article. I didn't know that the Beretta was so problematic. I have only heard that it is very reliable, even in sandy desert conditions.
I think the main downside of going from the 9mm to the .45 would be a loss of capacity. You just can't fit as many big fat rounds into the handle of a handgun. No combat handgun, with military spec ammo, has decent accuracy (3-1/2" groups at 25 yards would be impressive). Moreover, no one expects decent accuracy from a handgun. That's why the sights are fixed. In light of this, having lots of rounds is advantageous.
Keep us posted on any info about replacement of the M-9 or the 9mm.