Oostal

(...instead of continuing the old topic, where I started it, but it went too far from the original point, I state the question here.)

How does the Shimano 600 Ultegra sti shifter compare to newer Tiagra one? Would the newer, but lower end shifters function better than older one.

I ask because my bike has all Shimano 600 compnents (probably early 90s, dark grey), yet the shifters are from Tiagra. I saw locally a good deal on almost new looking Shimano 600 shifters (the same group as my derailleurs, with this three colored stripe under the name). I am tempted to get it as it looks so much better, but I have no idea, how it would function in comparison with my current set. Apart from one being 8 and the other 9-speed, what are the other differences?

bradtx

Oostal, The Sora and Tiagra are improvements over the groups they replaced (RSX, RX100), but still not at 600 tri color level, IMHO. Much of how the 600 shifters work will depend on their condition and previous owner's care so it's quite possible your Tiagra shifters will be better than these 600 shifters. To swap you'd also need a 8S cassette. You can buy them to have a matched full group, but save the Tiagra stuff.

Brad