I went back 4 days a week after both my oldest two and will be doing the same this time around, so not quite full time. I agree that you get much more efficient and also less perfectionist. It isn't that you don't care as much, just that your priorities are different, so a lot of the extra stuff you take on before having kids (extra curricular activities, extra responsibilities etc) takes a back seat for a while. I always find it hard when I hit the pressure points like coursework deadlines or exam times, but generally I have managed to make it work. I work most evenings but never at weekends. I only start working once the kids are in bed. I find the hardest thing actually, is not doing the marking / prep, but more balancing that with getting the school uniforms, sandwiches etc ready for the next day. This time around, I am going back into a management role which will be more responsibility and extra hours, but hardly any teaching. I am wondering how that will be in terms of time spent working at home. Hopefully better!