I cannot speak for the product itself, but I do have two things to offer: there is a slightly different model number (still from Orbit, and only 11% of those reviews are one star) which our venerable host has used a quantity of, and he might have something to offer up on the product. The other is that I have observed that product reviews on Amazon tend to be skewed on the negative end of the scale due to people being more inclined to give feedback when they had a negative experience instead of a positive one.
Said in reference to this post, whose Amazon link goes to the Orbit 62100, not the 62100Z.