optical zoom is better than digital zoom
but it depends how far away from your subject you will be.
50m or more get optical zoom
otherwise digital zoom would be ok
if it has an unsual type of battery check the check its "life" (a figure give in hours) and a camera that runs on a normal type of rechargable battery AA might be better if you travel alot,
if you forget the charger you can just keep some spares in the bag.