I believe that the consensus is that 1911s in 9mm are not as reliable as they are in 45 ACP. That does not mean they do not run but the odds of buying a problem child is much higher in 9mm than 45 ACP. They are even more mag dependent than the 1911 in 45 and we all know that the 1911 in 45 ACP is “The Worlds Finest Close Quarters Sidearm”… and, “King of feedway stoppages.” . LOL
I think a lot has changed in the last decade in terms of 9mm 1911 reliability. A number of manufacturers seem to have it pretty well figured out. I don't know what they have done, but I have seen a lot of people run 9mm 1911's that are pretty dang consistent.
Note that this is observation is based mostly on seeing people run 9mm 1911's in the single stack (minor) division of USPSA. That usually means that the users/competitors are loading their own ammo and aren't dropping guns in dirt. Maybe 9mm 1911's are still just as picky about nose profiles and OAL as many 45 1911's are, and the competitors are just good at controlling those variables. OTOH, these are generally guns that are run very hard - lots of extremely rapid shooting, sometimes with only a single hand on the gun, lots of slamming magazines home quickly, odd tilts/angles on the gun shooting around walls, etc.