As Rusty has said, QLab is an established standard, and it is used at all scales of theatre, and events, from the smallest community theatre to the largest Broadway shows and huge international events with TV audiences of millions. Also by using QLab you become part of a huge online community of users ( including users of this group, over 11000 on the unofficial FaceBook User group, and a large number of QLab users on other related forums). You can learn the basics of it in an afternoon, and when a really complicated show comes up you can look in detail at more advanced ways of using it.
Both programs have free versions and at the free level there is one huge difference. QLab is a fully functional program that you can program unlimited numbers of cues on and make some really sophisticated shows with , while MiX16 Go (the free version) only allows 64 audio cues (which they confusingly call channels) and you can't save anything at all!
MiX16Pro is substantially cheaper than QLab with a Pro License or multiple Pro Licenses, but for many uses the free version of QLab is actually better and easier to use than the Pro version of MiX16. Whether this is the case for you will depend very much on what you are intending to use software for in your production. Is it just to play house music and some spot effects during the play? Is it to play video for projection? Is it to play backing tracks for a musical? Do you need it to control hardware like a mixer? Do you need any individual sound to play to more than 2 audio outputs?
If the free version of QLab won't do everything you need for your show, then the price difference between the programs might come into play. But if you can afford the license for QLab or the modest daily rental charges, then QLab is in my opinion by far the better and most polished program and has many more features than MiX16, and is much easier to use.
My advice would be to sketch out a simple list in plain English of what cues you want to play from QLab, (post that list in this thread if you like and people may have some tips to help you). Download the free version of Qlab and watch the free tutorial videos here
https://qlab.app/tutorials and then program your show. If you get stuck with anything ask.
Finally a caveat. Because you have asked this question on a QLab forum you will not be surprised that any responses you get might be very pro QLab, although these responses are genuinely from real users of the product. You could ask the same question on a more general theatre forum, in an attempt to get a more balanced view, but I think the installed user base of MiX16 is very small indeed. Having said that, for some people it clearly works well for them, and although I have only looked at it very briefly, the developer has put a lot of thought and work into the program and it has some surprising features included for its price point.
But overall, I think that you and your students will enjoy using QLab more.
Mic