I agree that it's not a buggy pack. Been playing since release, have several households with horses, sheep and goats, and it's very smooth. Of course, this doesn't account for system issues that can cause blips or lag or general base game problems.
I have had the ranch hand issue, have had to rehire, sometimes they work into the night, but it honestly doesn't bother me that much, I don't find it invasive or anything. I use them all the time, I find them really necessary for households that have a lot of animals, and they've even helped care for my Cottage Living cows.
All in all, I love the horses, they will probably be my Sims' main mode of transportation from now on, even if we get cars one day. (Unless we get a horse and cart or carriage, which would be epic!)