When networx driver is installed calling winsock listen takes several hundred milliseconds, whereas normally (that is without networx driver) it takes only a few milliseconds. Because listen is relatively rare function to call it's not very prominent most of the time, however if an application trying to listen on many ports at once the (start up) delay is considerable.
I discovered this the hard way, and my story is here: http://stackoverflow.com/q/36687050/284111
Note: Please do not take word 'crap' that is used in the linked post personally, it is not attributed to networx or softperfect. It just describes my bad habits / bad discretion when it comes to choosing what I install on my machine. Again, it has nothing to do with networx or softperfect.
This is issue is not a deal breaker most of the time, but it would be extremely nice if it's fixed.