It can matter a great deal with a taildragger, especially if the gear retracts aft (Corsair, Hellcat, Warhawk etc.). It rarely matters much on a tricycle-geared model as the nose gear remains forward of the CG whether up or down.
ORIGINAL: RCFlyerDan
IHMO, with a tail dragger, it doesn't matter. The only time it matters is on a tricycle gear, due to retracted, the nose gear shifts the wt to a more tail heavy situation.