Thanks all for the info. Actually, I was looking closely at the group today, and am a bit confused... it's obviously an integrated and indexed system (not down-tube shifters), but all the components are labeled S.I.S. (including the integrated shifter/break levers). This seems to contradict what everyone said about S.I.S. being only down-tube and bar-end, since these are definately integrated. Could these perhaps be Shimano's first attempts at integrated systems, before S.T.I.?
Regardless, what I really want to know is will these shift as well as modern 105 S.T.I, or at least better than the Sora i'm using now. Since it sounds like even older 80's 105 is still running smoothly, I'm inclined to go with it.
One more question; how does the weight of these older components compare with what's being used today? Is it lighter than Sora? I know that it's the rider and not the bike that wins a race, but I would like to at least have comparable equipment to that of my competitors. Will this older groupo be a handicap?
Thanks again, I appreciate the advice.