Yeah it definitely varies by kid. My daughter was a sweetheart when she was 2.0, 3.0, 4.0, etc, but a terror at 2.5, 3.5, 4.5. Something about those half-year points, I don't know. My son, on the other hand, who is now 7, has been the easiest kid ever. Though that seems to be evolving a bit as he starts feeling a bit more independent, he's still overall a breeze compared to my daughter. I love her dearly, the precocious little girl she is, but she gives me gray hairs.
It seems a bit strange that the half-year points would matter... I wonder if it has to do with the season? For example, does your daughter like going outside and it's easier for you to go outside at the .0 than at the .5 because of the weather where you are?
I've got 5 kids between 1 and 7 years old (twin girls in the middle) and we've been pleasantly surprised with how easy they've been at each age (compared to what we'd prepared mentally for). We're "worst-case" preparers though.
Definitely depends significantly in the nature of the children, but also a significant part on the parents too.