It is one method, I prefer to use this over tissue/dope.
It also gives you a nice surface for painting.
It only works on sheeted surfaces, you can't use it over open structure parts.
You can cover the model in solortex or simular and then paint, but these iron on coverings take practise to apply on curved sections like wing tips. They add NO strength to the model and are not ding proof.
Than said I use this method on some of my small deltas and sport planes because it is quick, (once you get the hang of it), cheep, and comes in a variety of colours.
On my scale and aerobatic models, I use skinning cloth and resin.