I need some new shifters for my 8 speed shimano 600 tricolor group. I plan to buy some 9 speed shifters and utilize the alternate cable routing method to turn them into 8 speed.

I can get the Dura Ace in amazing condition for $120 or for $120 i can buy the Ultegra 6500 shifters AND brakes.

I have the ultegra brakes on my roubaix and love them. I don't know if some new pads and cables etc would make the 600's work just as well or if the 6500 is really better technology.

I would love the dura ace shifters but better stopping power is appealing too.

What do you guys think?

Assuming your 600 brakes are the dual pivots then decent pads would probably make them perform pretty similar. But if they are the old single pivot you would probably notice a difference.

The difference between 6400 brakes and 6500 brakes is just the finish. I have an all 6500 bike except for the brakes which are the old greenish 105SC's (same generation as 6400). They work just fine.

Come to think of it, I have 6500 and 7700 shifters on my two bikes. The 7700 is nicer, but you would never notice it unless you rode them back to back.