MU5TI " QuickSilver apparently doesn't learn which shortcuts I want to use for certain apps, whereas Launchbar does that."
It not only learns by itself, you can teach it, too. Everytime you select an app after typing the desired abbreviation, its score is increased. Do this a few times, and it'll be the first app to appear with that certain abbreviation. Or go ahead and assign your own abbreviation right away.
There's so much attention to detail in QS that it is mind-boggling. Butler is very good, LaunchBar was the original, but QS is head and shoulders above those two. Use it more than five minutes, and see for yourself.
(Version 1.8)