I used to use logitech headsets (G35 and 930) but made the move to the cloud IIs.
The surround sound is a bit better, and having inline rather than on ear control is a bit more convenient. The main difference is the weight and pressure. Both logitech headsets made my jaw start to hurt after extended sessions, as the metal band is very rigid and tight on my large head. Eventually this was resolved but it did last some time. My cloud IIs are by far the most comfortable headset ive worn. Light, flexible, and soft padding.
Sound quality is relatively even, cant decide one or the other there. The Cloud's mic can be quiet, so it has to be maxed out.
The clouds can also be used as stand alone headphones as well, due to the 3.5mm to USB dongle.