On my first machine debugging a device over activesync over USB was
extremely slow. Since I turned "allow network and RAS server connection" on
it is really fast, takes less then a second to move from one line to
another. Machine is P4 on 2.4GHz.
On my second machine which is 3.0Ghz debugging is fast eventhough the option
is not on. Wierd.
Devise has WiFi ofcourse.
Hope my experience might help to somebody....