When the ground gets real hard, mine actually will bounce. The tines go in as far as the ground will let them and if it's not deep enough, it will actually pick the whole unit up. It's not pretty but it's at least tough enough to take it.How does these machines hold up to hard ground and clay soils? I heard that they tear themselves apart in clay soils. I have a Classen TA-25, I'm just curious how the Plugr holds up in hard ground.