PanoSalado can display QTVR just fine -- it uses a PHP parser script to read in the QTVR and translate it to a Flash friendly format.
SpinControl:VR will let you use your existing QTVR files -- with or without the native QTVR lo-res previews -- in your virtual tour. Simply drag your QTVR (.mov) file onto the SpinControl Panorama pane (Tour:Panoramas:Panorama), and then set its settings like you would for any other VR in your tour.
Because the parser is PHP, it must be resident on a Web server in order to work. This means you will not be able to preview your QTVR based virtual tour in SpinControl:VR, or in the browser preview on your hard drive. You will need to upload your exported tour to your Web server in order to preview it.
If you are having trouble previewing in SpinControl:VR's "browser preview", but you're not using QTVR, please see this FAQ item)