There's sometimes a bit of chewing around the entrance, but nothing structural or that could not be patched with a little ingenuity. I've not used Apideas for comparison. The problem many have is the bees connecting the comb to the side walls. It has happened a bit to me, but nothing too significant. I prime mine with 300ml of bees and reuse them during the season, finally overwintering them as double deckers. It should be possible to get three queens mated per Kieler over the course of a normal (ha!) summer.