Properly made joint fittings don't break down or pull apart. No extra thickness or weight is needed to compensate for material removed by threading. Soldering is not difficult. Once you get the hang of it, it takes less than a minute to make a strong, leak-free joint that will last indefinitely. And it's a satisfying process.
Smooth bends let the tube follow contours and corners of almost any angle.
Soft temper tube, especially in renovation or modernization, requires much less wall and ceiling space and eliminates the need for joints in inaccessible areas. Mechanically formed tee connections allow branches to be formed faster and usually result in a lower installed system cost. Copper tube does not require the heavy thickness of threaded pipe with the same internal diameter, such as in natural gas distribution systems. Thus, copper costs less to transport, handles more easily, and takes less space when installed. Since copper is light and rigid, it doesn't sag over long runs, and it requires few supports.