(As always, feel free to send me a private message if you'd like me to post anonymously.)
I went back after 12 weeks at home because I kind of thought that was my only option. I liked my job, but wasn't in love with it; the joy of adult interaction and being out of the house was somewhat dampened by my wrestling matches with the pump; we had free grandparent childcare, or else it would not have been worth it. In somewhat of a backwards fashion, I worked until my younger son was 2, then have been home full-time since then...should have done it this way from the start. Live and learn :)