I like the API test kits as well. Not too expensive, and accurate enough for home aquarium use.
The only thing I dislike are the cheap glass test tubes they package with their kits. They're so thin and fragile that I have to assume they're intended to break and cause you to buy a new kit. (or at least another API test tube)
I've been using the plastic vials that came with my Tetra Laborett test kit after my cat broke most of my API vials.