CAPT...
I fly with it CAGED throughout the pattern, 'til I turn onto Final Bearing and then I un-CAGE it. I got this technique from the several Y/T videos on carrier landings. You can see the HUD caged and then around 0.8/0.7, it uncages and the ghost v/vector disappears. Personally, I like it, as the caged HUD helps me maintain my visual cues during the pattern but un-caged, I get the spot-on visual cues (v/vector on ship crotch) in the groove.
If you didn't already know, the HUD is fixed to where you can select a button to CAGE/UNCAGE your HUD, just like the jet. Its "cabin alert - seat belts on/off" under the FSX controls. Also, to enable it during flight, you must open the HUD Control Panel (shift-2) at least once. After that, the button will function regardless of panel visibility.
Hope this helps.
Later
Sludge