Actually it really isn't a problem. I wanted to also make sure that with all the hubbub about OS X 10.10 and higher that I hadn't introduced an additional problem. It doesn't seem to make any difference if the VSL software is running or removed on my system. So I'm good to go with either configuration. Thanks for giving me (us) a good answer. I've used the 1818VSL on a Windows based system for several years, even made several que mixes for independent mixes. The zero latency feature really works well. Only being able to use 16 inputs is a bit of a bummer but that is still a workable situation. I really like PreSonus products.