With a five inch long brake lever on an STI and the cable run through the unit you can probably do all kinds of fancy leverage/modulation stuff and brand-name it.
With a Dirty Harry ummm "notta so much"
edit there is a whole compatability chart of the new 6700/7900 Shimano stuff to last 6600/7800 etc. series that people are picking apart as being bollocks.
I have new 6700 cranks with old 105 front derailleur combo (there is a new 105 series soon) that Shimano say doesn't work together even though it does perfectly.
With a five inch long brake lever on an STI and the cable run through the unit you can probably do all kinds of fancy leverage/modulation stuff and brand-name it.
With a Dirty Harry ummm "notta so much"
edit there is a whole compatability chart of the new 6700/7900 Shimano stuff to last 6600/7800 etc. series that people are picking apart as being bollocks.
I have new 6700 cranks with old 105 front derailleur combo (there is a new 105 series soon) that Shimano say doesn't work together even though it does perfectly.