thank you, tim, mentor, sheldon. btw, sheldon, your site has been extremely helpful to me for a variety of problems i've encountered in the past, so thank you for that, as well.

i guess the deore front derailleur is the clear winner, then. i've posted mostly to thank y'all for your input, and to clear up an error i'd made in my original post: it's the bianchi axis, not the bianchi volpe, that runs a tiagra FD in conjunction with top-tube routing.

-rob