Advantage = -slightly- more displacement
Disadvatange = more money spent boring block, can't bore to fix block damage later on down the road
Just run the regular bore CTR pistons unless you have sleeve damage that needs an overbore to fix. If you use the larger bore pistons now, and you have something go wrong later that needs a slight bore to repair... you won't be able to do it and still use CTR pistons.
No extra head work is needed to run the oversize pistons, but you would need to slightly bore out your block to match.