Grab a cold beverage and pull up a chair. 
The answer to your questions (and pretty much all questions about technology) revolve around how free / libre / open the platform / technology / devices in question are. Which I think is a tangential question to openHAB (or any F/LOSS technology) but a very relevant one, not only as regards our hobbies and tech, but increasingly, socially and politically (once you spend time thinking about further implications). But I will try to stay on topic.
To my understanding, control4 is a pretty famously locked down technology. Besides, it is very expensive, way out of my price range. Those two factors have prevented me from spending any time investigating it further. You may have circumvented the latter (cost), but possibly not the former (freedom), which will potentially dramatically curtail it’s usefulness for you.
My anecdotal is: I have a (pretty wealthy at the time, now not as much so) buddy who had his whole house full of the stuff. He said he had to call the company who installed it every time he wanted to change something. Now he is not a dumb guy, so I don’t know if this was because it was locked down or what. </anecdotal.> And I don’t know the manner in which it is locked down (if at all) because I haven’t looked into it, for reasons stated above.
Now this may end up being a sunk cost for you (we all live and learn), but it is also an opportunity to analyze the underlying reasons why this happened, so we don’t make the same mistakes next time.
So in general I will state, that at the end of the day, the freedom aspect is much more important than the price. I am much more willing to pay a premium for free as in freedom hardware than I am for locked down stuff. In fact, at this point I absolutely refuse to purchase locked down stuff, because that is one of the few ways we have to influence anything, by voting with our feet / dollars. So now I not only exclusively purchase hardware which is well supported in GNU/Linux (and/or is pretty open and hackable in general), I make a point of trying to urge others to do the same (as I am doing in this post). Again, to me the cost is much less important than how open (free as in freedom) the platform is.
Therefore, when I discover something new, the first thing I usually do is to do a quick search for a couple things, depending on what sort of device it is:
- GNU/Linux (especially driver) support
- open bootloader / firmware (for embedded device or microcontroller)
- current state of F/LOSS libraries and/or reverse engineering effort (if there is enough interest, eventually it may become reality, unless the company/tech are really jerks and have decided to totally lock down the platform) which leads to
- general reputation of mfr. as regards above, their track record, willingness to engage in walled garden business strategies, etc.
A good example of this was my recent discovery of the Stream Deck, upon which the very first thing I did was to investigate the above issues, and then, only upon receiving positive confirmation, make a post sharing my findings (because I also do not personally believe in promoting non-free options, devices, etc…).
In my heavily considered opinion, when you start looking at things through the lens of free as in freedom instead of free as in price, everything starts to become clear. IMO, that is the only way that we can Have Nice Thingsâ„¢.
Don’t forget to share your findings, the results of your investigations and/or hacking efforts, as we are all standing on the shoulders of giants here. That is the other key part of insuring that we can all Have Nice Things™ going forward.