I've got a bike equipped with Biopace. My mechanic is strongly urging me to put a round chainring on (I'm converting the bike from mountain bike to commuter) so I was thinking of a touring crankset. Only there's that S.I.S. issue.

I do like the rapid fire shifters for commuting ease, but I've never liked the "system' approach that you get locked into with indexed shifting. So I suppose one objective would be to go to a round chainring but keep S.I.S., and the other would be to go to friction, so I can use whatever components I want.