The Gran Turismo does indeed get a bum rap. It was designed to be used on bikes with only one single chainring and a wide range freewheel. Contrary to most Japanese competitors, it is virtually indestructible and will rarely if ever need to be adjusted, a feature that fits in well with the target market for the derailleur. The Japanese derailleurs shift much better but are notoriously fragile and prone to need adjustment. The Campagnolo works well on those bikes sold to the large majority of weekend cyclists who do no maintenance to their bikes and have no technical understanding whatosever. In its day, it was not at all bad for its intended use. It does not however belong on any 'serious' bike.