I’ve had two generations of hori hori knives. I use them a lot. My first was a Niwaki smooth bladed one; the second was a Japeto with a serrated blade one side. I much prefer the second but probably entirely because of the cutting blade. Both are well made and probably both companies do serrated and smooth blades but I would definitely go for a serrated blade. I seem to need to cut through things quite frequently, but for more genteel gardening that might be less necessary!