An extruder gear never clicks, it is always the stepper. When the stepper clicks it means it is overloaded. Usually because of a filament clog, Nozzle trammed too close to the bed, or the hot end temp isn't hot enough to keep up with melting what the stepper is trying to feed it. The "newer" style isn't like a hobbed gear, it is a cast metal gear. A hobbed gear is machined to be like that. Generally the older style is better. Yes it does pick up some filament shavings, but the teeth are so sharp and hard it doesn't loose grip on the filament very easily. More spring tension helps also. Check out a filament feeder plastic I have on thingiverse under "jfkansas" it has better spring tension.