I haven't read all the threads, Jeangenie, and I know you're looking for positive experiences to back up your gut feel on jacking in the job... but I gave up working and am HATING it. With a vengeance. And it's putting a massive strain on our relationship because I'm so miserable.
I felt financially screwed once #2 arrived - why work for £30/day net (after tax/childcare/commute, etc) after a degree and a successful 11 year career?
There's a list of sacrifices when you juggle work and small kids...financial costs (childcare, slower promotion), emotional (lack of time with the kids), the effect on your career opportunities, and physical exhaustion. So if your job isn't right, it's natural to feel it isn't worth it. And, on paper, it was absolutely the right decision.
Now I've experienced SAHM'dom I'd PAY to get back into a half interesting job. (Unfortunately am 6 months pg so am unemployable for another 5 months realistically). I can't follow my other interests because the demands of the kids don't allow it yet, which obviously adds to the frustration.
If you love being with kids and are willing to get out and meet other mums, you'll probably love being at home. (you do learn to live on a tight budget).
I guess my advice would be: make sure your motivations are correct and that you'll really enjoy spending all your time with your kids. For me, it was the fastest route to madness.