I've been here on an open work permit as the partner of a grad student for nearly 3 years. I don't have kids, but yes, public education is free through the 12th grade and generally of good quality. I qualified for OHIP, the Ontario health program, which is free in the sense that tax dollars pay for it. My job gives me additional insurance that provides some money (but perhaps not all you need) for dental, eyeglasses, prescriptions, chiropractor, acupuncture, etc. That is also free to me.
The downside is, of course, the need to re-apply for the work permit periodically, and the idea that eventually, if I do not get permanent residence, I will have to pack up the life I've made for myself here and start over again somewhere else. Oh, and there are restrictions to having a work permit - I cannot study, for example, to increase my qualifications, and I am not eligible for many state-sponsored programs in my field that are open to permanent residents and citizens only.
