Qt Quick Controls 2.3 was released with Qt 5.10, and includes a variety of new features which make it better suited to developing certain types of desktop applications than the previous version of Qt Quick Controls 2, including nested menus and new supported themes to improve usability and look-and-feel on desktop platforms. You can see the announcement at the Qt Blog for more information about Qt Quick Controls 2.3. While many desktop applications are still best implemented with QtWidgets, there are good reasons to use Qt Quick (with Qt Quick Controls 2.3) instead of QtWidgets for some use-cases, especially where modern, animated user-interface elements are a key differentiating factor from the competition. Also, the ability to share large portions of your codebase (and look-and-feel) between desktop and mobile platforms makes Qt Quick a great choice when you have a multiple-form-factor solution for your customers!
If you are interested in developing an application with QtWidgets or with QtQuick, get in touch with us! As expert Qt developers with decades of experience developing both on and with Qt and QtQuick, we can estimate how much effort will be required, and provide information about which technology would best suit your use-case. One or more of our developers can work on your project independently, or integrate directly with your existing development team, to ensure the project is delivered with the highest quality.