Interesting article by John Morrissey in the May 2011 issue of Sport Aerobatics magazine. He and a colleague between them had ejected 4 times during their military careers. They did a little exercise - each 4 times. Sit in a Pitts S-2S for some time in a hangar then when some-one bangs on the fuselage start the activity - open canopy, remove headset, release two safety harnesses, stand up on the seat and get one leg out onto the wing walk. Their best time was 23 seconds to get out of this aeroplane.
Incidentally, I have used a cat collar to keep a headset on doing serious negative G until I saved up enough to buy a locally made leather "helmet" to suit a DC.
Like xgjunkie, my std DC stays on doing around -2 to +5.