It's such a dilemma...one we are constantly thinking about while on Mat Leave. While on Mat leave I have dropped DS2 to 1day care to 'keep me in' and will stop that when I make a final decision.
A friend made a very good point, she said and I quote "we got out numbered so I had to stay home" and she said that in a very positive way.
That's pretty much how I feel and your post is also sounding that way.
Are you a nurse kawazuki? Another friend dropped during the week work altogether and worked one shift a night on weekends and that seemed to make a difference.
I worked two days and I am due back in September...will ask for another 12mths and re-assess then. Is that a something you can do?