There's plenty of anecdote out there about mixing 1.3:1 levers with 1.4:1 calipers and vice versa, the consensus being that personal preference will be the determinant of whether you can live with the mismatch. Since he already has the ST-6700/BR-7800 combo, he might as well try it and change to BR-6700s if he doesn't like it.
There's plenty of anecdote out there about mixing 1.3:1 levers with 1.4:1 calipers and vice versa, the consensus being that personal preference will be the determinant of whether you can live with the mismatch. Since he already has the ST-6700/BR-7800 combo, he might as well try it and change to BR-6700s if he doesn't like it.