That Z series stuff... I think it's an interesting time in Shimano's lineup. I think that group was supposed to be a cross between a MTB and Touring set. I've seen it introduced on the Trek line on the sport bikes. It seems the Z206 FD was on tons of bikes. It worked welll as a double and it worked well as a triple AND half-step gearing. I have a set of the Z series drop bar brake levers. They're the second coolest looking brake levers evAr. Velobase has them listed as a part of the Golden Arrow 105 group. IMO the slotted Superbe levers are the coolest- but the Z306 levers are really cool. I also have a set of the 6207 600 series slotted levers- they're the same besides the 600 and Shimano logos.