Join Date: Apr 2010
Location: Warwick, UK
Bikes: 2000-something 3 speed commuter, 1990-something Raleigh Scorpion
You'll notice a difference between having 6 and 9-speed, but I doubt it will be significantly smoother. In my experience, cheap derailleurs shift just fine. More speed generally comes from a more powerful engine, not necessarily more and more gears- though they can help by allowing you to pedal in a narrower 'powerband'. If you're running out of high gears, changing the overall range of gears will help, which is best accomplished by larger front chainrings.