Here's my bias: I'm a SAHM. I've been a WAHM, WM, and I'll undoubtedly switch up my status from time to time again. Toe in every pool. For some time in each slot (years in each). Each has it' benefits and drawbacks. :)
I think working & motherhood is identical to working & fatherhood.
Except for the peculiar belief society holds that it's somehow different.
I don't know what I would do... it would depend on a LOT of factors, which change rather drastically in my own life year by year. I've worked because we've needed the money, I've stayed home because the money wasn't worth it. I've stayed home full time because I've wanted to, and I've worked because I've wanted to.
Really, in my experience, there is no "right" answer, except for whatever one you make.
PERSONALLY... I found that working full time suited my family best when my so was a toddler. Why? Because he was napping, and those naps made my work life and home life pretty "equal". He spent about the same time in care and the same time with me. It was a fun balance. Once he hit school... I only GOT three hours a day with him (I'm not including the hour of 'morning madness' where it's the 'get up-get dressed-eat-out the door-dropping off'... in his 12-13 hour waking day he was in school for 8 of them, and transported for 1-2 hours... leaving me 3 hours with him TOPS), and he was exhausted. Working full time for K would have been a nightmare. For other families, it's a perfect fit.
REALLY. No. Right. Answer. There are too many variables with needs and personality.