Welcome to the forum..

It depends on the vacation location. Are you talking about a cruise or beach vacation, then I would take the Olympus. With the waterproof feature being the key reason. As far as mega pixels, either one is fine since most are printed at 4x6, even and 8x10 will be fine.

Also it comes down to comfort, which camera feels better to you? That will be the camera that you will WANT to take everywhere with you.

Good luck and have fun,

James