when you press alt-f2 the first time, the runapp dialog is shown, but you cannot
enter anything for 4-5seconds ..i think he is searching for executables, for
which he offers autocompletion...

after the first time, the runApp can be used pretty fast, but after some time it
happens again ...

for me it makes the runApp dialog basically unusable.

either the autocompletion should be turned off
or
the search for executables could be done automatically at starting gnome
or
it should be done in the background when runapp is shown (so i can still enter
something into the dialog, if i know the exact name of the app)
or
at least a gconf key to be able to turn the search off

for example kde's runApp dialog does no autocompletion, but at least is fast.
that is much more usable for me.