If you want the ultimate in smooth, get the Happs perfect 360's.
The parts are even interchangable with Wico sticks, so if you're kinda crazy like me, you can even replace the bat handle with a ball-top. Feels closer to a leaf stick as well since there no microswitches to bump into.
Oh, small point, requires a +5V power line as well since it uses electronics rather than physical switches. Not hard to wire up though to your computer's power supply or I-PAC.