I'm somewhat new to smartphones and don't understand how data roaming works. I'm particularly concerned with it's effect on data usage. I'm also wondering if it significantly affects battery life, since my Vitality's battery drains rather quickly. (I have a new, "extended" battery on the way, so hopefully that will help out in that area.)

Does the Vitality (or any devices on Cricket Wireless) utilize data roaming, or would it be advisable for me to leave that option unchecked? If it does use roaming, what does enabling that function do? When I enable it, there's a warning about potential charges, but my assumption is that only applies to devices on contract carriers. Am I correct about this? Does the feature also eat up battery life quicker when it's enabled?