I always worked full time and my two children where looked after by au pairs and my parents. I felt guilty a lot of the time about not being with them, but has to work as I was a single parent. There was little choice. I was happy with my life, I loved my job and when I was with them we had great times together. They are all grown up now and funny enough they don't actually remember me not being there with them. They talk about the good times we had, holidays, parties, BBQ's which does exonerate my guilt so my answer to your question is if you are happy as a parent and and a person the time you spend with your children should be quality time.