Originally Posted by
dsbrantjr
You should not expect a startling performance improvement with such an upgrade.
+1. In fact, stepping up a level in Shimano front derailers is something of a step down. The more expensive derailers can be very finicky about set up. The cages tend to be narrower and more highly sculpted which makes them rub in more gears. The cheaper versions of
all Shimano front derailers (road and mountain) are better mechanisms.