have not used that one, but have used other rotating feeders before. it is a good idea to test them for a while first. if moisture can get into the food holding cannister easily than the food will clump to gether and not drop out properly.
how long will you be gone? If it's only a week then I wouldn't even sweat it; feed them well the day before you leave and I'd say they'd be fine. My tanks have always been fine for a weeks vacation. Otherwise see if a friend would stop by, you can set out premeasured containers of food so all they need to do is put in what's in the container.