Which Groupset?

You dont' need (or want) the Red front derailleur though do you?

agreed, i'd probably mix n match with a front force.

You should be getting very smooth shifting (by any standards) with 6600.
There were even a few moans about 6700's shifting when it came out (mostly sorted with cable routing though I think).

I've only minor irritations with the shifting, it's mainly the cable routing and hood shapes i hate.

Are the cables (either inners or outers) old?

[/QUOTE]
cables are 8 weeks old, lubed with sewing machine oil and are routed with ample room to manoeuvre.