I had a quick look at qt-openzwave. Up til now my home assistant is a simple pip virtenv based install (on a gentoo server).
To go the qt-openzwave route will be quite a bit more work. I will either have to install docker, which is possible but adds complexity to the server, or manually compile and install qt-openzwave which will be a lot of work to maintain. 
I think I’ll stick with the current default ZWave integration for as long as possible since it works fine.
It is on hold at the moment, but there are definitely moves to deprecate the non-supervisor methods for installing Home Assistant, so it might be worth looking at docker.
That said, check out the thread “The future of Z-wave in HA” as I am sure some in there are using virtenv installs and able to use this, though it may be a little more work to get it running.
I have a feeling, long term, the Home Assistant developers want to standardised Home Assistant to be one install method to make it easier to maintain, but who knows how long it will be before they do this.
There are no plans to deprecate the OZW 1.4 integration that is currently in HA, but do note the new integration uses OZW 1.6 and this does have a lot of new features and fixes, not to mention that the QT-OZW is a native OZW approach and bypasses the python wrapper for OZW.
It is a work in progress though 