Travel/every day use/

I have a cannon 550D but am travelling in june and as much as i would LOVE to take it with me, logistically it wouldnt be easy. I used to have a Olympus tough which since has died. I am stuck between these 2 cameras. Im leaning towards th s100 because once im back i could still use the canon for the fancy dancy pics.. would i be loosing a lot if i went with the s100? i think my main question is about the zoom, optical zoom is quite a diff...