I had 3x7 Microshift brifters on my 520 for a while, I thought they were fine. Not Ultegra STI level, as noted, but they worked well enough that they will end up on a 87 Trek 560 in the next month or so.

Only reason they aren't on the 520 anymore is because it is getting a 9 speed Ultegra upgrade and fancy new 130mm spacing.

EDIT: not sure if the pics still work in this thread........... http://www.bikeforums.net/classic-vi...-update-2.html