Same experiences as everyone else (always pay by CC for rewards points and the additional buyer protections).
In-stock: Charged full amount when game ships.
Wait-list games:
Pro/Premium: Charged a deposit (has always been $1k for me) upon placing order, remaining charged when game ships.
LE: You have to pay to play at this level, so expect to be charged the full amount up-front and be pleasantly surprised if you can get away with just a deposit; the exact terms probably depend on the title and whether or not you require any additional "special treatment" such as ability to pick the serial number.
