Pro Pedal, just increases the low speed compression damping making it harder for the shock to start moving and firmer, it's a good system but not 100% efficent.
The floodgate only works when the shock is locked out and it basically sets the amount of force required before the shock short term unlocks, so for XC you could lock it out and have a HT feel that kicks in on big bumps occasionally, or leave it off to DH stuff. Doesn't get you first bump plush though!!