I ran mine without one of the leaves for a couple of years. It didn't cause any problems, except that it lowered the back a little (didn't look as good, since the front wasn't lowered to match).

My goal was to make it ride a little smoother, which it did ... but only just a little. Not worth it in my opinion. I also cut new rubbing pads out of polypropylene to replace the worn-out abestos (?) pads that go between the ends of the leaves. It didn't help that I could tell.

For a smoother ride, apparently new springs is the way to go. Those fibreglass mono-leafs are supposed to make it ride more smoothly as well, too bad they are No Longer Available.