if you pedal at moderate cadences and its ok for you, perhaps its not worth it.
My experience was on a too heavily loaded touring bike, with rather diff hills so I was really forcing the issue, and my knees on the steep hills with not enough of low gearing. In fact, after this trip I changed the range of gearing on my bike, so that it would have lower climbing gears, AND I reduced the weight of my things by a good amount for my next trip.
and I am pretty certain that I would pedal quickly often, making the weird "up and down" feeling in my knees uncomfortable.
you can do some tests to see how it feels, but I would caution keeping the cadence moderate. what cadence I cant be specific, but listen to your knees. I certainly wouldnt ride on biopace ever again.