I went back with DS1 when he was nearly 11 months. I did 1 day per week for the first month & am now 2.5 days per week, plus I work for myself 1 day per week.
Why did I return? I wanted to keep my job (been there 11 years) and keep my skills up & my options open. I also like being able to contribute financially, so I haven't had to give away my (expensive) hobby completely. Still being able to keep my horses & do some work outside the home has kept me sane and my life balanced. I am older (mid 30s) so had planned ahead & worked hard to ensure I wouldn't have to sacrifice *all* the things I enjoy (there were plenty of compromises!!).
I am enjoying being a Mum - we are expecting baby #2 in September. I will work 4 days/week in the lead up for financial reasons, then take 12 months mat leave & only plan to return 1 day a week for the first 6 months, then ideally go onto a 3 day fortnight whilst I have 2 children under kinder age. Hubby also plans to cut back his hours so we can reduce days at childcare. We've accepted we'll have a couple of years of lower income - but it's not forever. We both want to spend lots of time with the children whilst they are small.
Long term, 2 days at work I think would be perfect for me - best of both worlds.