Lugs were also used in most low-end frames until Tig welding took over in the 1980s. Lugs themselves do not make a frame good but high end lugged frames are a thing of beauty:
A quality lugged bike will have the lugs sculpted to diffuse stress over a wide areas. Some people take artistic licence with the sculturing:
http://www.bohemianbicycles.com/Gallery's.htm
http://columbinecycle.com/photo_gallery.html

For more info on frame construction see lug-maker:
http://www.henryjames.com